Rotary electric machine

Abstract

To provide a rotary electric machine that secures motor strength and has improved cooling performance.SOLUTION: A rotary electric machine 10 comprises: a shaft 160 connected to a stator 130 and a rotator 150; a rotational shaft 151 connected via a cylindrical rotor core holding part 155; a plurality of permanent magnets 152 provided in the rotational shaft 151; and the rotator 150. The shaft 160 includes a first coolant flow channel 161; and a communication hole 170 that communicates between the first coolant flow channel 161 and the rotor core holding part 155. The rotor core holding part 155 includes: a second coolant flow channel 162 extending to an outer peripheral side of the rotator 150 via the communication hole 170; a third coolant flow channel 163 branching in a circumferential direction of the rotator 150 from the second coolant flow channel 162; a fourth coolant flow channel 164 leading to the permanent magnets 152 from the third coolant flow channel 163; and a fifth coolant flow channel 165 extending along the permanent magnets 152 from the fourth coolant flow channel 164.SELECTED DRAWING: Figure 3

Description

Technical Field

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

Background Art

[0002] In recent years, due to the trend of CO2 reduction, in order to realize a zero-carbon society, CO2 emission regulations are strongly demanded in various countries. As an alternative to engines that use fossil fuels and emit CO2, electrification that does not emit CO2 during the operation of the power system is actively promoted. In all engine-driven mobility products, an improvement in the output density for future power electronic devices is required.

[0003] Therefore, it is essential to be able to cope with all climates around the world, and in the case of aircraft, environmental resistance that can cope with rapid altitude changes is required. At the same time, technical responses such as improving cooling performance, increasing voltage, reducing weight, and increasing speed are required.

[0004] Here, as a cooling method for the motor, there is an oil cooling method with high cooling performance. This is a method in which oil flows inside the motor to cool heat-generating parts such as permanent magnets, rotor cores, and stator coils. Although this oil cooling method can improve the cooling performance because the heat-generating part can be directly cooled by providing a flow path, on the other hand, the structure may become complicated in order to form the oil flow path.

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

[0006] In Patent Document 2, a flow path provided along the central axis of the shaft, a through-flow path provided in a direction perpendicular to the shaft axis at the portion where the rotor core and the shaft are connected, and a flow path provided through the rotor core along the inner surface of the permanent magnet are connected to each other, forming a series of through-flow paths. By supplying cooling oil to this flow path by an oil pump, the rotor core and the permanent magnet are cooled. That is, similar to Patent Document 1, the object is to provide a motor with high cooling performance.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0008] However, in the above prior art, since a flow path penetrating the fixed member of the motor is provided and configured such that the refrigerant oil flows, there is a problem that the structure is complex and difficult to machine. Furthermore, in a motor for an aircraft, since the rotational speed is high and the load torque is large, if there are a plurality of through-holes in the fixed member of the motor, the motor strength may decrease, leading to a risk of failure of the electric system.

[0009] An object of the present invention is to provide a rotating electrical machine having a simple and easy-to-machine cooling structure, ensuring motor strength and improving cooling performance, and an electric aircraft equipped with this rotating electrical machine.

Means for Solving the Problems

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

[0011] The rotating electrical 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 via a cylindrical rotor core holding portion centered on the shaft, and a plurality of permanent magnets inserted into the rotor core, and includes a rotor disposed via a gap from the stator. 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. The rotor core holding portion communicates from the first refrigerant flow path through the communication hole, and has a second refrigerant flow path provided on the surface of the rotor core holding portion and extending to the radially outer peripheral side of the rotor, 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.

[0012] In addition, the electric aircraft mounts the above rotating electrical machine.

Advantages of the Invention

[0013] According to the present invention, in the rotor core holding portion of the motor, by providing simple and easily machined grooves and flow paths, a rotating electrical machine with ensured motor strength and improved cooling performance, and an electric aircraft equipped with this rotating electrical machine can be provided.

[0014] Problems, configurations, and effects other than those described above will be clarified by the description of the following embodiments.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2A

Figure 2B

Figure 2C

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Mode for Carrying Out the Invention

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

Examples

[0017] <Example 1> With reference to FIGS. 1 to 6, the rotating electrical machine (motor) according to Embodiment 1 of the present invention will be described.

[0018] FIG. 1 is a schematic plan view of an electric aircraft 100 equipped with the motor according to Embodiment 1 of the present invention seen from above.

[0019] In the first embodiment, an electric aircraft 100 is assumed that generates thrust by using a motor 10 (see FIG. 2) that rotates a propeller and an inverter 20 (see FIG. 2) that supplies power to the motor 10, and the rotors 201 to 203 and 301 to 303 of the propeller.

[0020] FIG. 2 shows a schematic diagram showing a part of a cooling circuit such as a motor (rotating electrical 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 drives the propellers 201 to 203 and 301 to 303 by using an inverter 20 (see FIG. 2) that supplies power to the motor 10, and generates thrust. Further, as shown in FIG. 1, the electric aircraft 100 includes a fuselage (airframe) 101, propellers 201, 202, 203 on the left side of the fuselage 101, and propellers 301, 302, 303 on the right side of the fuselage 101.

[0022] The electric system (power component) for driving the left propellers 201 to 203 and the right propellers 301 to 303 includes a motor 10 (10a to 10f) and an inverter 20 (20a to 20f). The inverter 20 (20a to 20f) converts the DC power of the power supply into AC power and supplies the drive current to the motor 10 (10a to 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 the power supply. The inverter 20 converts the DC power from the power storage device into AC power suitable for the motor 10 (10a to 10f).

[0024] The power storage device is composed of, for example, a capacitor or a secondary battery such as a lithium ion battery or a nickel metal hydride battery. The power transfer between the power storage device and the motor 10 is performed via the inverter 20.

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

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

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

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

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

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

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

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

[0033] With the above configuration, the cooling systems 700a, 700b, and 700c include refrigerant pipes 70a to 70c through which a refrigerant that cools a plurality of motors 10a to 10f and a plurality of inverters 20a to 20f flows, pumps 60a to 60f that are connected to the refrigerant pipes 70a to 70c and send out the refrigerant, and radiators 50a to 50c that are connected to the refrigerant pipes 70a to 70c and release the heat of 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 Example 1 as seen from the side, and FIG. 4 is a schematic plan view of the rotor 150 of the motor according to Example 1 as seen from directly above in the axial direction of the shaft 160. FIG. 5 is a schematic cross-sectional view of a part of the rotor 150 of the motor 10 according to Example 1 as seen from the side, and FIG. 6 is a schematic cross-sectional view of a part of the rotor 150 of the motor 10 according to Example 1 as seen from directly across in the radial direction.

[0035] As shown in FIG. 3, the motor 10 has a cylindrical stator (stator) 130 fixed to the housing 191, a cylindrical rotor 150 (rotor) rotatably arranged with a gap from the stator 130, and a shaft 160 connected to the rotor 150. The rotor 150 is arranged on the inner peripheral side of the stator 130.

[0036] In this specification, the "axial direction", "circumferential direction", and "radial direction" are as follows. The "axial direction" is the direction along the rotation center axis of the rotor 150 (hereinafter also referred to as the rotation axis) O (shown in FIG. 3). The "circumferential direction" is the direction along the rotation direction of the rotor 150, that is, the circumferential direction centered on the rotation axis O. The "radial direction" is the direction orthogonal to the rotation axis O, that is, the radial direction of the circle centered on the rotation axis O. Further, the "inner circumferential side" refers to the inner side in the radial direction, and the "outer circumferential side" refers to the opposite direction, that is, the outer side in the radial direction.

[0037] The stator 130 includes 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 sheets. The stator core 131 is fitted and fixed inside the housing 191.

[0038] A plurality of (72 in the first embodiment) slots parallel to the central axis direction of the stator core 131 are formed in the inner circumferential portion of the stator core 131. Teeth are formed between the slots. The slots are parallel slots having side surfaces parallel to each other along the radial direction of the stator core 131. That is, the slots have a constant circumferential width from the outer peripheral end to the tip of the teeth. A plurality of phase windings of the U-phase, V-phase, and W-phase that constitute 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 plurality of teeth are formed so as to project from the annular core back toward the rotation axis O. The teeth form a magnetic path in the radial direction, and the core back forms a magnetic path in the circumferential direction. The teeth guide the rotating magnetic field generated by the coil 132 to the rotor 150 and generate a rotational torque in the rotor 150.

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

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

[0042] As shown in FIGS. 3 and 4, the rotor core 151 is formed, for example, by laminating a plurality of annular electromagnetic steel sheets. The permanent magnet 152 forms the field poles of the rotor 150. For the permanent magnet 152, a neodymium-based, samarium-based sintered magnet, a ferrite magnet, a neodymium-based bonded magnet, etc. can be used.

[0043] Rectangular parallelepiped-shaped magnet insertion holes are formed at equal intervals in the circumferential direction near the outer peripheral portion of the rotor core 151. The permanent magnet 152 is embedded in each magnet insertion hole and fixed with an adhesive or the like. In the first embodiment, as shown in FIG. 7, the I-shaped permanent magnets 152a extending in the radial direction and the single-letter-shaped permanent magnets 152b in the circumferential direction are alternately arranged to form a Halbach array (66 poles in the first embodiment). Thereby, the torque of the motor is improved. In FIGS. 3, 4, and 5, for the sake of illustration, the permanent magnets 152a and 152b are shown simplified as the permanent magnet 152.

[0044] Also, the rotor core holding portion 155 is annular and is attached together with the rotor core 151 so as to close a part of the magnet insertion holes. The rotor core 151 and the permanent magnet 152 are axially pressed by the rotor core holding portion 155, and the axial position is regulated. Aluminum or the like can be used for the rotor core holding portion 155.

[0045] Also, as shown in FIGS. 3 and 4, the shaft 160 is a cylindrical member extending along the axial direction, and has a flow path (hereinafter also referred to as the first refrigerant flow path) 161 through which oil as a refrigerant flows inside. That is, a plurality of communication holes 170 that communicate the first refrigerant flow path 161 with the outside of the shaft 160 are formed in the shaft 160. The communication holes 170 are provided on the surface of the rotor core holding portion 155 and extend to the radially outer peripheral side of the rotor 150 (hereinafter referred to as the second refrigerant flow path) 162. The second refrigerant flow path 162 communicates with the first refrigerant flow path 161 through the communication holes 170. The dimensions, width, and shape of the first refrigerant flow path 161 are determined based on the flow rate of the refrigerant used and the pressure loss.

[0046] Also, as shown in FIGS. 4 and 5, the second refrigerant flow path 162 is connected to a groove (hereinafter referred to as the third refrigerant flow path) 163 formed by branching in the vicinity of the outer peripheral portion of the magnet insertion hole and in the vicinity of 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 the third refrigerant flow path 163 that branches in the circumferential direction, the number of the second refrigerant flow paths 162 extending in the radial direction can be made smaller than the number of the permanent magnets 152, ensuring the rotor strength. The number of the third refrigerant flow paths 163 is also smaller than the number of the permanent magnets 152.

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

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

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

[0050] The fourth refrigerant flow path 164 extends from the third refrigerant flow path 163 to the radially outer peripheral side of the rotor 150 and reaches the permanent magnet 152. The fourth refrigerant flow path 164 is also connected to a fifth refrigerant flow path 165 that extends along the permanent magnet 152. The fifth refrigerant flow path 165 has an upper refrigerant flow path 165U that extends from the connection portion with the fourth refrigerant flow path 164 to the upper surface portion of the permanent magnet 152, and a lower refrigerant flow path 165L that extends to the lower surface portion of the permanent magnet 152. Further, the fifth refrigerant flow path 165 not only branches vertically, but also has an upper surface portion flow path 152SU formed on the upper surface portion of the permanent magnet 152, a lower surface portion flow path 152SL formed on the lower surface portion of the permanent magnet 152, and a flow path extending in the axial direction of the rotor core 151 of the permanent magnet 152. With the fifth refrigerant flow path 165, the area for cooling the permanent magnet 152 can be increased, and the cooling effect can be improved. An opening that is open in the vertical direction (axial direction) is formed in the fifth refrigerant flow path 165, and from this opening, the refrigerant is discharged, discharged from the oil discharge hole 300, and circulated via 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 of the refrigerant used and the pressure loss.

[0051] As shown in FIGS. 5 and 6, for the fifth refrigerant flow paths 165a and 165b, the oil guided from the shaft 160 through each refrigerant flow path is directly applied to the I-shaped permanent magnet 152a and the one-character-shaped permanent magnet 152b, so that the cooling performance can be improved. Also, in view of the influence of the pressure loss, the widths of the fifth refrigerant flow paths 165a and 165b are the same in dimension and width at the upper and lower branches. However, the dimensions and widths of both may be changed as appropriate according to the operating conditions (required specifications, required output), and the same effect can be obtained.

[0052] With the above configuration, since the number of grooves and through-holes in the rotor core holding portion 155 is reduced as much as possible, it is possible to ensure the rotor strength even when the motor 10 is driven at high speed.

[0053] Therefore, according to Embodiment 1 of the present invention, it is possible to provide a cooling structure that is simple and easy to process, and a rotating electrical machine capable of ensuring motor strength and improving cooling performance, and an electric aircraft equipped with this rotating electrical machine.

[0054] <Example 2> With reference to FIG. 8, the motor 10 according to Embodiment 2 of the present invention will be described. In FIG. 8, the same or corresponding parts as those in Embodiment 1 are denoted by the same reference numerals, and the differences will be described.

[0055] FIG. 8 is a schematic plan view of the rotor 150 of the motor 10 according to Embodiment 2 as viewed from directly above in the axial direction.

[0056] In Embodiment 2, the surface grooves of the second refrigerant flow path 162 and the third refrigerant flow path 163 are a piping flow path 400 covered with a resin material such as a rubber packing material. As a result, oil can be guided to the outer peripheral side from the first refrigerant flow path 161 and the communication hole 170 by the centrifugal effect of the rotor 150, and the processing grooves of the rotor core holding portion 155 can be further reduced, improving the sealing performance. Therefore, the refrigerant oil can be more efficiently guided to the rotor core 151 and the permanent magnet 152, and it is possible to ensure the motor strength and improve the cooling performance.

[0057] Note that the piping passage 400 of the rubber packing does not extend to the third refrigerant flow path 163 and may be used in a state where it is extended only partway.

[0058] According to Embodiment 2, in addition to obtaining the same effects as those in Embodiment 1, the above-described effects can be obtained.

[0059] <The Third Embodiment> Referring to FIG. 9, the motor 10 according to Embodiment 3 of the present invention will be described. In FIG. 9, the same or corresponding parts as those in Embodiment 1 are denoted by the same reference numerals, and the differences will be described.

[0060] FIG. 9 is a schematic cross-sectional view of a part of the rotor of the rotating electrical machine according to Embodiment 3 as viewed from the side.

[0061] The differences between Embodiment 3 shown in FIG. 9 and Embodiment 1 shown in FIG. 3 will be described. In Embodiment 1 shown in FIG. 3, the fifth refrigerant flow path 165 branches from the fourth refrigerant flow path 164 in both directions (the vertical direction in FIG. 9). However, in Embodiment 3 shown in FIG. 9, the refrigerant flow path 165 extends from the fourth refrigerant flow path 164 in one direction (the downward direction in FIG. 9). That is, the refrigerant flow path 165 has a lower refrigerant flow path 165L, but does not have an upper refrigerant flow path 165U. Other configurations are the same as those shown in FIG. 3.

[0062] When the motor 10 is applied to the electric aircraft 100, the refrigerant is less likely to flow upward compared to the downward direction. Therefore, by adopting the configuration in which the refrigerant extends in one direction from the fourth refrigerant flow path 164, the circulation speed of the refrigerant can be increased and the cooling effect can be improved.

[0063] Also in Embodiment 3, the same effects as those in Embodiment 1 can be obtained.

[0064] <Modification of Embodiment 3> In Embodiment 3, the refrigerant flow path 165 extends from the fourth refrigerant flow path 164 in one direction.

[0065] In the modification of Embodiment 3, similar to Embodiment 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 refrigerant is less likely to flow upward compared to the downward direction. Therefore, by adopting the above configuration, the circulation speed of the refrigerant can be increased and the cooling effect can be improved.

[0067] Even in the modification of Example 3, the same effects as those of Example 3 can be obtained.

[0068] As described above, the embodiments of the present invention have been explained. However, the above embodiments merely show a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

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

Explanation of Reference Numerals

[0070] 10 (10a, 10b, 10c, 10d) ··· motor (rotating electrical machine), 20 (20a, 20b, 20c, 20d, 20e, 20f) ··· inverter, 50 (50a, 50b, 50c) ··· radiator, 60 ··· pump, 70 ··· refrigerant pipe, 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 portion flow path, 152SL ··· lower surface portion 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 stator comprising a cylindrical stator core and a coil mounted on 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, A rotating electrical machine comprising: 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, wherein the rotor core holding portion communicates from the first refrigerant flow path through the communication hole, and has a second refrigerant flow path provided on the surface of the rotor core holding portion and extending to the outer peripheral side in the radial direction of the rotor, communicates with the second refrigerant flow path, and has a third refrigerant flow path provided on the surface of the rotor core holding portion and branching from the second refrigerant flow path in the circumferential direction of the rotor, extends from the third refrigerant flow path to the outer peripheral side in the radial direction of the rotor and reaches the permanent magnet, and a fourth refrigerant flow path, and a fifth refrigerant flow path extending along the permanent magnet from the fourth refrigerant flow path. The rotating electrical machine is characterized by this.

2. In the rotating electrical machine according to claim 1, 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. The rotating electrical machine is characterized by this.

3. In the rotating electrical machine according to claim 1, 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. The rotating electrical machine is characterized by this.

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

5. In the rotating electrical machine according to claim 1, 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. The rotating electrical machine is characterized by this.

6. In the rotating electrical machine according to claim 1, 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. The rotating electrical machine is characterized by this.

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

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

9. In the electric aircraft according to claim 8, 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, a plurality of radiators connected to the plurality of refrigerant pipes and releasing the heat of the refrigerant, characterized by comprising.

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