Cooling structure of rotary machine

Abstract

To provide a cooling structure of a rotary machine which can achieve compactification and reduction of the weight of the rotary machine itself while securing cooling of the rotary machine during operation.SOLUTION: A cooling structure of a rotary machine cools a motor 1 having a shaft 3 which extends along a predetermined axis V, centered on the axis V during operation of the motor 1. The cooling structure includes a cooling pump 7 which is disposed on the axis V in a housing 8 of the motor 1 and rotates integrally with the shaft 3 to be operated and thereby circulate a refrigerant for cooling the motor 1. The cooling pump 7 has: a driving gear 21 which is configured to be rotatable around the axis V and rotates integrally with the shaft 3; and a driven gear 22 which engages with the driving gear 21 and rotates in conjunction with rotation of the driving gear 21.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a cooling structure for a rotating machine, and is applicable to a rotating machine such as a motor that drives a rotor blade of a drone, and relates to a cooling structure for a rotating machine that cools the rotating machine during its operation.

Background Art

[0002] Conventionally, as a cooling structure for this type of rotating machine, for example, those described in Patent Documents 1 and 2 are known. The rotating machine of Patent Document 1 is an axial-gap type rotating electric machine, and includes a rotor attached to the rotating shaft in a state where the rotating shaft penetrates therethrough, a stator arranged with a gap in the axial direction of the rotating shaft with respect to the rotor, and a case that houses the rotor and the stator. The case is provided with an introduction port for introducing a coolant and a discharge port for discharging the coolant, which communicate the inside and outside of the case. Thereby, the stator in the case is cooled by the coolant introduced through the introduction port, and the coolant that has exchanged heat with the stator is discharged to the outside through the discharge port.

[0003] On the other hand, the rotating machine of Patent Document 2 is a drive device composed of a radial-type motor, and includes a rotor attached to the motor shaft in a state where the motor shaft penetrates therethrough, a stator arranged with a gap in the radial direction with respect to the rotor, a housing that houses the rotor and the stator, a pump unit provided in the housing for circulating cooling oil in the housing, and a transmission member for transmitting the rotation of the motor shaft to the pump unit. The pump unit includes a pump shaft arranged parallel to the motor shaft, an external gear fixed to the lower end of the pump shaft and having a plurality of teeth on the outer peripheral side, and an internal gear formed in a ring shape and having a plurality of teeth on the inner peripheral side and meshing with the external gear. A trochoid pump is constituted by these components. Further, the transmission member has two meshing gears, and the rotation of the motor shaft is transmitted to the pump shaft through both gears, so that the pump unit operates.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the rotary machine of Patent Document 1, the coolant is circulated inside and outside the rotary machine by a pump disposed outside the rotary machine via an introduction port and a discharge port provided in the case. Therefore, a drive source for driving the pump is required, and in addition, the cooling structure of the rotary machine including the pump becomes large-sized.

[0006] On the other hand, in the rotary machine of Patent Document 2, since the pump section is driven by the rotation of the motor shaft of the rotary machine itself, unlike the rotary machine of Patent Document 1, a dedicated drive source for the pump section is not required. However, in the rotary machine of Patent Document 2, since the pump shaft of the pump section is arranged at a distance from the motor shaft in the radial direction thereof, a transmission member composed of gears is essential, and accordingly, the rotary machine itself becomes large-sized and heavy.

[0007] The present invention has been made to solve the above problems, and an object thereof is to provide a cooling structure for a rotary machine that can achieve downsizing and weight reduction of the rotary machine itself while ensuring cooling of the rotary machine during operation.

Means for Solving the Problems

[0008] In order to achieve the above object, the invention according to claim 1 is a cooling structure for a rotating machine having a rotating shaft that extends along an axis centered on a predetermined axis, the cooling structure cooling the rotating machine during its operation. In the housing of the rotating machine, a cooling pump is provided that is arranged on the axis and operates by rotating integrally with the rotating shaft to circulate a refrigerant for cooling the rotating machine. The cooling pump is configured to be rotatable about the axis and has a drive gear that rotates integrally with the rotating shaft and a driven gear that meshes with the drive gear and rotates as the drive gear rotates.

[0009] According to this configuration, in the housing of the rotating machine, a cooling pump that operates by rotating integrally with the rotating shaft is arranged on the above axis. Thereby, compared with the conventional cooling structure including a pump for circulating the coolant outside the rotating machine, the cooling structure of the rotating machine including the cooling pump can be configured compactly. Further, the above cooling pump has a drive gear and a driven gear that meshes with the drive gear, and the drive gear is configured to be rotatable about the above axis and rotates integrally with the rotating shaft. Therefore, in the cooling structure of the rotating machine of the present invention, unlike the conventional cooling structure in which the pump shaft is arranged at a distance in the radial direction from the motor shaft, transmission members such as gears are not required, and accordingly, the rotating machine itself can be made more compact and lighter.

[0010] The invention according to claim 2 is the cooling structure of the rotating machine according to claim 1, wherein the rotating machine further has a rotor that can rotate integrally with the rotating shaft with the rotating shaft passing through, and a stator that is arranged at a predetermined interval in the axial direction with respect to the rotor. Further, a refrigerant pipe through which the refrigerant flows when circulating the refrigerant between the cooling pump and the stator is provided so as to be exposed to the outside from the housing.

[0011] According to this configuration, the rotating machine has the above-described rotor and stator, and the stator is arranged at a predetermined interval in the axial direction with respect to the rotor. That is, since the rotating machine is an axial-gap type rotating machine, compared with a radial-type rotating machine in which the rotor and the stator have a gap in the radial direction of the axis, the rotating machine can be configured compactly and high torque can be obtained. Further, since the refrigerant for cooling the rotating machine circulates between the cooling pump and the stator, the stator that generates heat during the operation of the rotating machine can be cooled well. In addition, since the refrigerant pipe through which the above refrigerant flows is provided so as to be exposed to the outside from the housing, when the refrigerant flows through the refrigerant pipe, the temperature of the refrigerant can be easily lowered by heat exchange with the outside air.

[0012] The invention according to claim 3 is the cooling structure of the rotating machine according to claim 2, wherein the cooling pump is an internal gear pump, the driving gear is composed of an inner rotor having a plurality of teeth along the outer peripheral surface, and the driven gear is formed in a ring shape surrounding the inner rotor and is composed of an outer rotor having a plurality of teeth having more teeth than the inner rotor along the inner peripheral surface.

[0013] According to this configuration, since the cooling pump is an internal gear pump, the cooling pump can be configured more compactly than in the case of being configured by an external gear pump. Further, since the driving gear and the driven gear of the cooling pump are respectively composed of the above-described inner rotor and outer rotor, when the inner rotor rotates in a predetermined direction integrally with the rotating shaft of the rotating machine, the outer rotor can be rotated in the same direction while realizing a smooth pump operation in the cooling pump.

[0014] The invention according to claim 4 is the cooling structure of the rotating machine according to claim 3, wherein the housing has an outer rotor holding portion inside thereof for rotatably holding the outer rotor around an eccentric axis parallel to the axis and displaced in the radial direction, and the outer rotor holding portion is provided with a suction port for sucking refrigerant and a discharge port for discharging refrigerant on the side opposite to the rotating shaft in the axial direction.

[0015] According to this configuration, since an outer rotor holding portion for rotatably holding an outer rotor about the above eccentric axis is provided in the housing of the rotating machine, when the rotating machine is operating, as the inner rotor that rotates integrally with the rotating shaft rotates, the outer rotor engaged therewith can be smoothly rotated. Further, since the outer rotor holding portion is provided with a suction port for sucking the refrigerant and a discharge port for discharging the refrigerant on the side opposite to the rotating shaft in the axial direction, the refrigerant can be easily sucked and discharged on the same side in the axial direction by the cooling pump.

[0016] The invention according to claim 5 is characterized in that, in the cooling structure of the rotating machine according to claim 3, the rotating shaft has a refrigerant guiding flow path for guiding the refrigerant discharged from the cooling pump through the inside of the rotating shaft to the stator.

[0017] According to this configuration, since the refrigerant guiding flow path is provided in the rotating shaft, the refrigerant discharged from the cooling pump can be easily guided to the stator through the refrigerant guiding flow path.

[0018] The invention according to claim 6 is characterized in that, in the cooling structure of the rotating machine according to claim 5, the refrigerant guiding flow path has a first guiding flow path that extends along the axis by a predetermined length and has one end opening on the cooling pump side, and a second guiding flow path that communicates the other end of the first guiding flow path with the stator and extends along the radial direction of the axis.

[0019] According to this configuration, the refrigerant guiding flow path in the rotating shaft has the above first guiding flow path and second guiding flow path. The refrigerant discharged from the cooling pump flows into one end of the first guiding flow path and flows in the length direction of the rotating shaft through the first guiding flow path. Then, the refrigerant reaching the other end of the first guiding flow path flows into the second guiding flow path, flows in the radial direction of the rotating shaft, and is guided to the stator. In this case, while the rotating shaft rotates, the refrigerant is sent out to the outside in the radial direction of the rotating shaft, so that the stator can be effectively cooled while the refrigerant is sent out radially.

[0020] The invention according to claim 7 is the cooling structure of the rotary machine according to claim 6, wherein the housing has, inside thereof, an outer rotor holding portion that rotatably holds an outer rotor about an eccentric axis parallel to the axis and offset in the radial direction, and the outer rotor holding portion is provided with a suction port for sucking refrigerant on the side opposite to the rotation axis in the axial direction, and a discharge port for discharging refrigerant is provided on the rotation axis side in the axial direction, and the discharge port is connected to one end portion of the first guide flow path.

[0021] According to this configuration, since an outer rotor holding portion that rotatably holds the outer rotor about the eccentric axis is provided inside the housing of the rotary machine, when the rotary machine operates, the outer rotor meshing therewith can be smoothly rotated along with the rotation of the inner rotor that rotates integrally with the rotation axis. Further, since the above suction port and discharge port are provided in the outer rotor holding portion, the refrigerant sucked through the suction port can be smoothly discharged through the discharge port into the first guide flow path in the rotation axis.

[0022] The invention according to claim 8 is the cooling structure of the rotary machine according to claim 2, wherein the rotation axis has, inside thereof, a hole portion that extends a predetermined length along the axis and has a predetermined diameter and opens inward of the housing, and a relative rotation member that is rotatable relative to the rotation axis about the axis is provided in the hole portion, the cooling pump is an internal gear pump, the drive gear is constituted by an outer rotor portion having a plurality of teeth along the inner peripheral surface of the opening in the hole portion of the rotation axis, the driven gear is rotatably supported by the relative rotation member and is constituted by an inner rotor having a plurality of teeth along the outer peripheral surface and having fewer teeth than the outer rotor portion, and the relative rotation member is provided with a third guide flow path that penetrates along the axis and guides the refrigerant to a refrigerant temporary storage portion provided between the inner rotor side, the back wall of the hole portion, and the relative rotation member and temporarily storing the refrigerant, and the rotation axis is provided with a fourth guide flow path that communicates the refrigerant temporary storage portion with the stator and extends along the radial direction of the axis.

[0023] According to this configuration, a relative rotation member that is rotatable relative to the rotating shaft is provided in the hole provided in the rotating shaft. That is, the relative rotation member can be held stationary even when the rotating shaft rotates. Further, since the cooling pump is an internal gear pump, the cooling pump can be configured more compactly than in the case of being configured by an external gear pump. Furthermore, since the drive gear and the driven gear of the cooling pump are respectively constituted by the above outer rotor part and the inner rotor, when the outer rotor part integrally rotates with the rotating shaft of the rotating machine in a predetermined direction, a smooth pump operation can be realized in the cooling pump while rotating the inner rotor in the same direction.

[0024] Also, since the third guide flow path is provided in the relative rotation member and a refrigerant temporary storage portion is provided between the back wall of the rotating shaft and the relative rotation member, the refrigerant sucked by the cooling pump is sent to the refrigerant temporary storage portion in the rotating shaft through the third guide flow path. And since a fourth guide flow path that communicates the refrigerant temporary storage portion with the stator is provided in the rotating shaft so as to extend along the radial direction of the axis, by the rotation of the rotating shaft, the stator can be effectively cooled while radially sending out the refrigerant in the refrigerant temporary storage portion through the fourth guide flow path.

[0025] The invention according to claim 9 is the cooling structure of the rotating machine according to claim 8, wherein the relative rotation member has a main body portion formed in a columnar shape extending along the axis and having a third guide flow path, and a support portion that protrudes from the main body portion to the opening side of the hole and rotatably supports the inner rotor around an eccentric axis displaced radially from the axis.

[0026] According to this configuration, the relative rotating member has the above-mentioned main body portion and support portion, a third guide flow path is provided in the main body portion, and the inner rotor is rotatably supported by the support portion. Thereby, it is possible to easily align the position where the refrigerant is discharged due to the rotation of the outer rotor portion and the inner rotor with the refrigerant inlet in the third guide flow path, and thereby, the refrigerant from the cooling pump can be appropriately sent out to the refrigerant temporary storage portion through the third guide flow path.

[0027] The invention according to claim 10 is the cooling structure of the rotary machine according to claim 9, wherein the support portion is inserted into the inner rotor in a state of being loosely inserted through the central portion thereof, and on one side and / or the other side in the length direction of the support portion in the inner rotor, bearings are provided for rotatably holding the inner rotor while supporting it in the length direction of the support portion.

[0028] According to this configuration, since the inner rotor with the support portion of the relative rotating member loosely inserted into the central portion can rotate while being supported in the length direction of the support portion by the above-mentioned bearings, it is possible to stably rotate the inner rotor while avoiding local temperature rise caused by the sliding of the rotating inner rotor against other members.

[0029] The invention according to claim 11 is the cooling structure of the rotary machine according to claim 10, wherein the support portion has a refrigerant introduction flow path for introducing the refrigerant into the interior from its tip, and a refrigerant supply port that is continuous with the refrigerant introduction flow path and opens to the outside in the radial direction of the support portion for supplying the refrigerant introduced into the refrigerant introduction flow path to the gap between the support portion and the inner rotor.

[0030] According to this configuration, a refrigerant introduction passage for introducing refrigerant into the support portion of the relative rotating member is provided from its tip. Further, the support portion is provided with a refrigerant supply port that is continuous with the refrigerant introduction passage and opens to the outside in the radial direction of the support portion. The refrigerant introduced into the refrigerant introduction passage of the support portion flows out from the refrigerant supply port and is supplied to the gap between the support portion and the inner rotor, specifically, between the outer peripheral surface of the support portion and the inner peripheral surface of the inner rotor. By using, for example, cooling oil as the refrigerant, an oil film for lubrication can be easily formed in the gap between the support portion and the inner rotor. Thereby, when the inner rotor rotates, stable rotation of the inner rotor can be ensured while preventing seizure and the like accompanying sliding between the outer peripheral surface of the support portion and the inner peripheral surface of the inner rotor.

[0031] The invention according to claim 12 is characterized in that, in the cooling structure of the rotary machine according to claim 11, the inner rotor has a refrigerant supply passage that penetrates in the radial direction thereof and further supplies the refrigerant supplied from the refrigerant supply port to the meshing portion between the inner rotor and the outer rotor portion.

[0032] According to this configuration, since the inner rotor is provided with a refrigerant supply passage that penetrates in the radial direction thereof, the refrigerant supplied from the refrigerant supply port flows through the refrigerant supply passage and is further supplied to the meshing portion between the inner rotor and the outer rotor portion. As a result, an oil film for lubrication is formed on the tooth surface of the meshing portion between the inner rotor and the outer rotor portion, so that smooth meshing of both rotors can be achieved and the temperature rise of the meshing portion can be effectively suppressed. As a result, a stable pump operation can be ensured by the rotation of the inner rotor and the outer rotor portion.

Brief Description of the Drawings

[0033]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0034] Hereinafter, with reference to the drawings, preferred embodiments of the present invention will be described in detail. FIG. 1 is a diagram for explaining the cooling structure of a rotating machine according to the first embodiment of the present invention. In the figure, (a) shows a longitudinal sectional view of a motor that drives the rotating blades of a drone, for example, to which the cooling structure is applied.

[0035] As shown in FIG. 1(a), this motor 1 (rotating machine) is arranged below the rotating blades 2 of a drone (not shown), and rotates and drives the rotating blades 2 around the vertical axis V (predetermined axis). The rotating blades 2 have a plurality of blades extending horizontally from the central part by a predetermined length, and the central part is fixed to the upper end of a shaft 3 of the motor 1 described later.

[0036] The motor 1 is an axial-gap type motor, and includes a shaft 3 (rotating shaft) extending a predetermined length along the vertical axis V, two upper and lower rotors 4 and 5 fixed to the shaft 3 in a state where the shaft 3 penetrates therethrough and rotatable integrally with the shaft 3, a stator 6 disposed between the two rotors 4 and 5 in a state where the shaft 3 is inserted therethrough, a cooling pump 7 provided below the shaft 3 for circulating cooling oil (refrigerant) for cooling the motor 1, and a housing 8 that houses the above-mentioned shaft 3, both rotors 4 and 5, the stator 6, and the cooling pump 7.

[0037] The shaft 3 is formed in a columnar shape having a predetermined length and diameter, and is provided so as to protrude upward from an opening 8a provided in the ceiling wall of the housing 8. Further, the lower end portion of the shaft 3 is rotatably supported by an outer rotor holding portion 23, which will be described later, via a shaft bearing 10 composed of a thrust bearing.

[0038] The upper and lower rotors 4 and 5 are configured to be vertically symmetric with each other and are arranged at a predetermined distance in the vertical direction. In the following description, the upper rotor 4 will be referred to as the "upper rotor 4" and the lower rotor 5 will be referred to as the "lower rotor 5" as appropriate.

[0039] The upper rotor 4 has a disk-shaped rotor core 4a having a through-hole in the central portion, and a plurality (only two are shown in FIG. 1(a)) of permanent magnets 4b fixed in a state of being arranged along the circumferential direction on the lower surface of the rotor core 4a. On the other hand, the lower rotor 5 has a rotor core 5a similar to the above-mentioned rotor core 4a, and a plurality (only two are shown in FIG. 1(a)) of permanent magnets 5b fixed in a state of being arranged along the circumferential direction on the upper surface of the rotor core 5a.

[0040] Further, the upper rotor 4 is fixed to the shaft 3 through the through-hole of the rotor core 4a, and is rotatably provided in the housing 8 via an upper bearing 11 composed of a radial bearing. On the other hand, the lower rotor 5 is fixed to the shaft 3 in the same manner as the upper rotor 4 described above, and is rotatably provided in the housing 8 via a lower bearing 12 composed of a radial bearing.

[0041] The stator 6 has a predetermined thickness in the vertical direction and has a box-shaped stator core 6a whose planar shape is formed in a donut shape, and a plurality (12 in FIG. 1(c)) of coils 6b arranged along the circumferential direction while being exposed vertically from the upper wall and the lower wall of the stator core 6a. The stator 6 faces the upper rotor 4 and the lower rotor 5 in the vertical direction. More specifically, each coil 6b of the stator 6 faces between the permanent magnet 4b of the upper rotor 4 and the permanent magnet 5b of the lower rotor 5 with a predetermined gap therebetween.

[0042] The cooling pump 7 is composed of an internal gear pump. Specifically, as shown in FIGS. 1(b) and 1(d), the cooling pump 7 includes an inner rotor 21 (drive gear) fixed to the lower end of the shaft 3, an outer rotor 22 (driven gear) provided on the outer peripheral side of the inner rotor 21 and meshing with the inner rotor 21, and an outer rotor holding portion 23 provided in the housing 8 and rotatably holding the outer rotor 22.

[0043] The inner rotor 21 is formed to have a predetermined thickness and outer diameter, and has a plurality (five in FIG. 1(d)) of teeth along the outer peripheral surface. On the other hand, the outer rotor 22 is formed in a ring shape having a predetermined thickness, outer diameter, and inner diameter, and has a plurality (six in FIG. 1(d)) of teeth with one more tooth number than the inner rotor 21 along the inner peripheral surface. These inner rotor 21 and outer rotor 22 are constituted by trochoid gears. In FIG. 1(d) (including (d) in FIGS. 2 to 8 and (c) in FIGS. 9 to 12), for the sake of illustration, the hatching at the center of the inner rotor 21 is omitted to show the vertical axis V and the eccentric axis E.

[0044] The outer rotor holding portion 23 has a recess 23a having a diameter substantially the same as the outer diameter of the outer rotor 22. With an eccentric axis E offset in the radial direction from the vertical axis V as the center, the outer rotor 22 is rotatably accommodated in the recess 23a. Further, on the bottom wall 24 of the outer rotor holding portion 23, there are provided an inlet 24a for sucking cooling oil and an outlet 24b for discharging cooling oil, both of which penetrate in the vertical direction.

[0045] As shown in FIG. 1(b), inside the housing 8, a cooling oil storage chamber 25 for storing cooling oil is provided between the bottom wall 8b thereof and the outer rotor holding portion 23. Further, this cooling oil storage chamber 25 is partitioned by a partition wall 26 that continues between the bottom wall 8b of the housing 8 and the bottom wall 24 of the outer rotor holding portion 23. Thereby, the cooling oil storage chamber 25 is partitioned into a suction chamber 25a facing the inlet 24a and a discharge chamber 25b facing the outlet 24b.

[0046] Also, as shown in FIG. 1(a), on the motor 1, two cooling oil pipes (refrigerant pipes) 27, 28 for circulating cooling oil are provided substantially symmetrically on the left and right so as to be exposed to the outside of the housing 8. The first cooling oil pipe 27 on the left side shown in FIG. 1(a) is attached to the side wall of the housing 8 so as to communicate the stator core 6a with the discharge chamber 25b inside the housing 8. On the other hand, the second cooling oil pipe 28 on the right side shown in FIG. 1(a) is attached to the side wall of the housing 8 so as to communicate the stator core 6a with the suction chamber 25a inside the housing 8.

[0047] Next, in the motor 1 configured as described above, the flow of the cooling oil during its operation will be described. FIGS. 2(a) to (d) respectively correspond to FIGS. 1(a) to (d) described above, and the flow of the cooling oil is indicated by arrows.

[0048] Electricity is supplied to the motor 1 from the outside, and when current flows through each coil 6b of the stator 6, the shaft 3 rotates in a predetermined direction integrally with the upper rotor 4 and the lower rotor 5. As a result, the rotating blade 2 fixed to the shaft 3 also rotates in the same direction as the shaft 3.

[0049] Also in this case, as the shaft 3 rotates, the cooling pump 7 in the housing 8 operates, and thereby, the stator 6 of the motor 1 is cooled by the circulating cooling oil. Specifically, when the shaft 3 when viewing the motor 1 from above rotates, for example, in the clockwise direction, as shown by the white arrow in Fig. 2(d), the inner rotor 21 rotates in the clockwise direction about the vertical axis V integrally with the shaft 3. Along with this, the outer rotor 22 meshing with the inner rotor 21 rotates in the same direction as the inner rotor 21 about the eccentric axis E. As a result, in the cooling pump 7, the cooling oil is sucked upward from the suction chamber 25a through the suction port 24a, and the cooling oil is discharged into the lower discharge chamber 25b through the discharge port 24b. Then, the cooling oil sent out from the cooling pump 7 to the discharge chamber 25b circulates in the motor 1 as follows.

[0050] That is, as shown in Figs. 2(a) and (b), the cooling oil sent out from the cooling pump 7 to the discharge chamber 25b flows to the stator 6 through the first cooling oil pipe 27. As shown in Fig. 2(c), the cooling oil flowing into the stator core 6a of the stator 6 from the first cooling oil pipe 27 flows between the outer side and the inner side in the radial direction of each coil 6b, and between the adjacent coils 6b, 6b as shown by the arrow in the figure, and flows into the second cooling oil pipe 28. Then, as shown in Fig. 2(a), the cooling oil flowing through the second cooling oil pipe 28 flows into the suction chamber 25a and is sucked in again through the suction port 24a of the cooling pump 7.

[0051] As described above, the cooling oil circulates in the motor 1 and exchanges heat with each coil 6b of the stator 6, thereby effectively cooling each coil 6b.

[0052] As described in detail above, according to the present embodiment, since the cooling pump 7 that rotates integrally with the shaft 3 is disposed within the housing 8 of the motor 1, the motor 1 itself including the cooling pump 7 can be made more compact and lighter in weight compared to the prior art. Further, since the axial gap type is adopted as the motor 1, the motor 1 can be configured to be even more compact and high torque can be obtained compared to the radial type. Furthermore, since an internal gear pump having an inner rotor 21 and an outer rotor 22 is adopted as the cooling pump 7, the cooling pump can be configured compactly and smooth pump operation can be realized in the cooling pump 7.

[0053] Next, with reference to FIGS. 3 and 4, a second embodiment of the present invention will be described. In the present embodiment, mainly the structures of the shaft 3, the stator 6, and the cooling pump 7 are different from those of the motor 1 of the first embodiment. Therefore, in the following description, the same components as those in the first embodiment will be denoted by the same reference numerals, and detailed description thereof will be omitted, and the description will focus on the differences from the first embodiment.

[0054] As shown in FIGS. 3(a) and (b), the stator core 6a of the stator 6 is connected to the shaft 3 in a relatively rotatable state via two upper and lower bearings. Specifically, the stator core 6a has an upper wall 6au and a lower wall 6ad, both of which are formed in a donut shape in plan view, and these upper wall 6au and lower wall 6ad are respectively connected to the shaft 3 in a relatively rotatable state via an upper bearing 13 and a lower bearing 14, both of which are radial bearings. Note that the upper bearing 13 and the lower bearing 14 have a predetermined sealing property so that the cooling oil does not leak from inside the stator core 6a to the outside.

[0055] Also, as shown in FIGS. 3(a) to 3(c), inside the shaft 3, there is provided a cooling oil guiding flow path 31 (refrigerant guiding flow path) for guiding the cooling oil sent out from the cooling pump 7 to the stator 6. Specifically, the cooling oil guiding flow path 31 is formed in a cylindrical shape extending a predetermined length along the vertical axis V, and has a first guiding flow path 31a opening to the lower cooling pump 7 side, and a second guiding flow path 31b extending in the radial direction of the vertical axis V and communicating the upper end portion of the first guiding flow path 31a with the inside of the stator 6.

[0056] The cooling pump 7 has an inner rotor 21 and an outer rotor 22 similar to those in the first embodiment, and the outer rotor 22 is rotatably held by the outer rotor holding portion 23. Also, between the inner rotor 21 and the outer rotor 22 and the lower end portion of the shaft 3, there is provided a pump cover 29 fixed to the outer rotor holding portion 23.

[0057] A through hole 29a is formed at the center of the pump cover 29, and the lower end portion of the shaft 3 protruding downward through the through hole 29a is fixed to the inner rotor 21. Also, at a predetermined position of the pump cover 29, a discharge port 29b penetrating in the vertical direction is provided. Further, the shaft 3 is rotatably supported by the pump cover 29 via the shaft bearing 10.

[0058] FIGS. 4(a) to 4(d) respectively correspond to FIGS. 3(a) to 3(d) described above, and similar to FIG. 2 described above, the flow of the cooling oil is indicated by arrows. Similar to the first embodiment described above, when electricity is externally supplied to the motor 1 and current flows through each coil 6b of the stator 6, the shaft 3 rotates in a predetermined direction integrally with the upper rotor 4 and the lower rotor 5, and accordingly, the cooling pump 7 in the housing 8 operates.

[0059] Specifically, when the shaft 3 of the motor 1 is seen from above and rotates, for example, in the clockwise direction, as indicated by the white arrow in Fig. 4(d), the inner rotor 21 rotates clockwise about the vertical axis V integrally with the shaft 3. Accordingly, the outer rotor 22 meshing with the inner rotor 21 rotates in the same direction as the inner rotor 21 about the eccentric axis E. As a result, in the cooling pump 7, the cooling oil is sucked upward from the cooling oil storage chamber 25 through the suction port 24a and discharged upward through the discharge port 29b of the pump cover 29. Specifically, it is discharged downward into the first guide flow path 31a of the cooling oil guide flow path 31 in the shaft 3. Then, the cooling oil sent out from the cooling pump 7 to the cooling oil guide flow path 31 circulates in the motor 1 as follows.

[0060] That is, as shown in Figs. 4(a) and (b), the cooling oil sent out to the first guide flow path 31a in the shaft 3 through the discharge port 29b of the cooling pump 7 flows upward along the first guide flow path 31a. When it reaches the second guide flow path 31b located at the upper end thereof, it flows to the outside in the radial direction of the shaft 3, that is, into the stator core 6a of the stator 6. In this case, as the shaft 3 rotates, the second guide flow path 31b rotates, and the cooling oil flows out from the second guide flow path 31b. Therefore, as shown in Fig. 4(c), the cooling oil flows radially outward around the shaft 3 and between the adjacent coils 6b, 6b. The cooling oil passing between the coils 6b, 6b flows along the outer peripheral wall of the stator core 6a and flows into the first cooling oil pipe 27 and the second cooling oil pipe 28. Then, as shown in Fig. 4(a), the cooling oil flowing through both the cooling oil pipes 27 and 28 flows into the cooling oil storage chamber 25 in the housing 8 and is sucked in again through the suction port 24a of the cooling pump 7.

[0061] As described above, the cooling oil circulates in the motor 1 and exchanges heat with each coil 6b of the stator 6, thereby effectively cooling each coil 6b.

[0062] As described in detail above, according to this embodiment, the same effects as those of the first embodiment described above can be obtained. Further, in this embodiment, since the cooling oil is caused to flow radially from the shaft 3, each coil 6b can be cooled, and all the coils 6b can be cooled more effectively.

[0063] Next, with reference to FIGS. 5 and 6, a third embodiment of the present invention will be described. In this embodiment, the structures of the shaft 3 and the cooling pump 7 are different from those of the motor 1 in the first and second embodiments. Therefore, in the following description, the same reference numerals will be given to the same components as those in the first and second embodiments, and the detailed description thereof will be omitted, and the description will be centered on the differences from the first and second embodiments.

[0064] As shown in FIGS. 5(a) and 5(b), inside the shaft 3, a hole portion 41 is provided which extends along the vertical axis V for a predetermined length and has a predetermined diameter, and opens inward of the housing 8, that is, below the shaft 3. On the inner peripheral surface of the opening at the lower end of the hole portion 41, an outer rotor portion 42 (drive gear) having a plurality of teeth similar to those of the outer rotor 22 in the first and second embodiments described above and meshing with an inner rotor 44 to be described later is provided. Further, in the hole portion 41, a relative rotation member 43 that is rotatable relative to the shaft 3 about the vertical axis V is provided.

[0065] This relative rotation member 43 has a main body portion 43a formed in a columnar shape having a predetermined length and diameter, and a support portion 43b formed in a columnar shape that protrudes downward from the lower surface of the main body portion 43a by a predetermined length and has a predetermined diameter smaller than that of the main body portion 43a.

[0066] The main body portion 43a of the relative rotation member 43 is rotatably supported in the hole portion 41 via two upper bearings 45 and lower bearings 46, both of which are radial bearings, with a predetermined distance from the ceiling surface 41a (rear wall) of the hole portion 41 of the shaft 3. Further, at a predetermined position of the main body portion 43a, a guide flow path 43c (third guide flow path) that penetrates in the vertical direction and guides the cooling oil upward is provided.

[0067] On the other hand, the support portion 43b of the relative rotating member 43 projects downward from the lower surface of the main body portion 43a around an eccentric axis E that is parallel to the vertical axis V and displaced in the radial direction. The support portion 43b is loosely inserted into the central portion of an inner rotor 44 (driven gear) similar to the inner rotor 21 of the first and second embodiments described above, and rotatably supports the inner rotor 44. Further, the support member 43b passes through the bottom wall 24 of the outer rotor holding portion 23, and the lower end portion thereof is supported by a support recess 8c provided in the bottom wall 8b of the housing 8.

[0068] A cooling oil temporary storage portion 47 (refrigerant temporary storage portion) for temporarily storing cooling oil is provided between the relative rotating member 43 configured as described above and the ceiling surface 41a of the hole portion 41 of the shaft 3. The shaft 3 is provided with a guide flow path 48 (fourth guide flow path) that extends along the radial direction of the vertical axis V and communicates the cooling oil temporary storage portion 47 with the inside of the stator 6.

[0069] FIGS. 6(a) to (d) respectively correspond to FIGS. 5(a) to (d) described above, and similar to FIGS. 2 and 4 described above, the flow of the cooling oil is indicated by arrows. Similar to the first and second embodiments described above, when electricity is externally supplied to the motor 1 and current flows through each coil 6b of the stator 6, the shaft 3 integrally with the upper rotor 4 and the lower rotor 5 rotates in a predetermined direction. Along with this, the cooling pump 7 in the housing 8 operates.

[0070] Specifically, when the shaft 3 as viewed from above the motor 1 rotates, for example, in the clockwise direction, as indicated by the white arrow in FIG. 6(d), the outer rotor portion 42 rotates clockwise about the vertical axis V integrally with the shaft 3. Along with this, the inner rotor 44 meshing with the outer rotor portion 42 rotates in the same direction as the outer rotor portion 42 around the eccentric axis E. As a result, in the cooling pump 7, the cooling oil is sucked upward from the cooling oil storage chamber 25 through the suction port 24a and discharged upward from below to the guide flow path 43c of the relative rotating member 43. In this case, the relative rotating member 43 is held stationary.

[0071] The cooling oil sent out to the guide channel 43c by the cooling pump 7 flows through the guide channel 43c, rises, and is stored in the cooling oil temporary storage part 47. Then, the cooling oil sent from the cooling pump 7 to the cooling oil temporary storage part 47 through the guide channel 43c circulates in the motor 1 as follows.

[0072] That is, as shown in FIGS. 6(a) and (b), the cooling oil sent from the cooling pump 7 to the cooling oil temporary storage part 47 through the guide channel 43c of the relative rotating member 43 flows through the guide channel 48 of the shaft 3 to the outside in the radial direction of the shaft 3, that is, into the stator core 6a of the stator 6. In this case, as shown in FIG. 6(c), the cooling oil flows radially outward around the shaft 3 between the adjacent coils 6b, 6b and flows into the first cooling oil pipe 27 and the second cooling oil pipe 28, similar to the second embodiment described above. Then, as shown in FIG. 6(a), the cooling oil flowing through both the cooling oil pipes 27 and 28 flows into the cooling oil storage chamber 25 in the housing 8 and is sucked in again through the suction port 24a of the cooling pump 7.

[0073] In the above manner, the cooling oil circulates in the motor 1 and exchanges heat with each coil 6b of the stator 6, so that each coil 6b can be effectively cooled.

[0074] As described in detail above, according to this embodiment, the same effects as those of the first and second embodiments described above can be obtained. Further, in this embodiment, the cooling oil from the cooling pump 7 can be appropriately sent out to the cooling oil temporary storage part 47 in the shaft 3 through the guide channel 43c of the relative rotating member 43.

[0075] Next, with reference to FIGS. 7 and 8, a fourth embodiment of the present invention will be described. The motor 1 of this embodiment is configured such that the inner rotor 44 of the cooling pump 7 is supported by bearings in the length direction of the support portion 43b of the relative rotation member 43 with respect to the motor 1 of the third embodiment. In the following description, the same components as those in the above-described embodiments will be denoted by the same reference numerals, and detailed descriptions thereof will be omitted, and the description will focus on the differences from the third embodiment.

[0076] As shown in FIGS. 7(a) and (b), an upper bearing 51 (bearing) and a lower bearing 52 (bearing) each composed of a thrust bearing are provided above and below the inner rotor 44, respectively. Specifically, the upper bearing 51 is disposed in a sandwiched state between the lower surface of the main body portion 43a of the relative rotation member 43 and the upper surface of the inner rotor 44. On the other hand, the lower bearing 52 is disposed in a sandwiched state between the lower surface of the inner rotor 44 and the upper surface of the bottom wall 24 of the outer rotor holding portion 23. FIGS. 7(c) and (d) are cross-sectional views taken along the c-c line and the d-d line of the motor 1 in FIG. 7(a), respectively.

[0077] FIGS. 8(a) to (d) respectively correspond to FIGS. 7(a) to (d) described above, and similar to FIGS. 2, 4, and 6 described above, the flow of the cooling oil is indicated by arrows. As shown in FIG. 8, in the motor 1 of this embodiment, the cooling oil circulates in the same manner as the motor 1 of the third embodiment described above, and heat exchange is performed with each coil 6b of the stator 6, whereby each coil 6b can be effectively cooled.

[0078] As described above, according to the present embodiment, by providing the upper bearing 51 and the lower bearing 52 above and below the inner rotor 44, the inner rotor 44 can rotate while being supported in the length direction of the support portion 43b of the relative rotation member 43 (the vertical direction in FIGS. 7 and 8(a) and (b)). Therefore, it is possible to stably rotate the inner rotor 44 while avoiding a local temperature rise caused by the rotating inner rotor 44 sliding against other members, for example, the lower surface of the main body portion 43a of the relative rotation member 43 or the upper surface of the bottom wall 24 of the outer rotor holding portion 23.

[0079] Next, referring to FIGS. 9 and 10, a fifth embodiment of the present invention will be described. The motor 1 of the present embodiment is configured such that, in the support portion 43b of the relative rotation member 43 with respect to the motor 1 of the fourth embodiment, the cooling oil introduced from the tip thereof is supplied to the gap between the support portion 43b and the inner rotor 44. In the following description, the same reference numerals are given to the same components as those in the above-described embodiments, and the detailed description thereof is omitted, and the description will be centered on the differences from the fourth embodiment.

[0080] As shown in FIGS. 9(a) and (b), in the support portion 43b of the relative rotation member 43, there are provided a cooling oil introduction passage 53 (refrigerant introduction passage) for introducing cooling oil into the inside from the tip (the lower end in FIGS. 9(a) and (b)), and a cooling oil supply port 54 (refrigerant supply port) for supplying cooling oil to the gap between the support portion 43b and the inner rotor 44.

[0081] Further, FIG. 9(c) is a cross-sectional view taken along the c-c line of the motor 1 in FIG. 9(a), and FIG. 9(d) shows an enlarged view of the central portion of the cross-sectional view in FIG. 9(c). As shown in FIGS. 9(b) and (d), the cooling oil introduction passage 53 extends a predetermined length along the length direction of the support portion 43b and opens into the lower cooling oil storage chamber 25. The cooling oil supply port 54 is continuous with the upper end portion of the cooling oil introduction passage 53 and opens to the outside in the radial direction of the support portion 43b. Specifically, the cooling oil supply port 54 is provided so as to face the inner peripheral surface 44a of the inner rotor 44 with a gap therebetween.

[0082] Figs. 10(a) to (d) correspond to Figs. 9(a) to (d) described above, and similar to Figs. 2, 4, 6, and 8 described above, the flow of the cooling oil is indicated by arrows. As shown in Fig. 10, in the motor 1 of the present embodiment, the cooling oil circulates in the same manner as the motor 1 of the third embodiment described above, and heat exchange is performed with each coil 6b of the stator 6, whereby each coil 6b can be effectively cooled.

[0083] Also, although not shown, in the housing 8 of the motor 1, the cooling oil is always stored up to a predetermined height (for example, near the upper surface of the inner rotor 44). Therefore, in the motor 1, as shown in Figs. 10(b) and (d), the cooling oil is introduced through the cooling oil introduction passage 53 of the support portion 43b of the relative rotation member 43, and the introduced cooling oil flows out from the cooling oil supply port 54 of the support portion 43b.

[0084] As described above, according to the present embodiment, the cooling oil flowing out from the cooling oil supply port 54 is supplied between the outer peripheral surface of the support portion 43b and the inner peripheral surface 44a of the inner rotor. With the supplied cooling oil, an oil film for lubrication can be easily formed in the gap between the support portion 43b and the inner rotor 44. Thereby, when the inner rotor 44 rotates, stable rotation of the inner rotor 44 can be ensured while preventing seizure or the like accompanying sliding between the outer peripheral surface of the support portion 43b and the inner peripheral surface of the inner rotor 44.

[0085] Next, with reference to Figs. 11 and 12, a sixth embodiment of the present invention will be described. The motor 1 of the present embodiment is configured such that, in the inner rotor 44 of the cooling pump 7 of the motor 1 of the fifth embodiment, the cooling oil supplied from the cooling oil supply port 54 in the support portion 43b of the relative rotation member 43 is further supplied to the meshing portion between the inner rotor 44 and the outer rotor portion 42. In the following description, the same components as those in the above-described embodiments will be denoted by the same reference numerals, and detailed description thereof will be omitted, and the description will focus on the differences from the fifth embodiment.

[0086] As shown in FIGS. 11(a) and (b), the inner rotor 44 is provided with a cooling oil supply passage 55 (refrigerant supply passage) that penetrates in the radial direction. Specifically, as shown in FIG. 11(d), the cooling oil supply passage 55 is provided so as to extend from the inner peripheral surface 44a of the inner rotor 44 toward the recess on the outer peripheral surface. In FIG. 11(d), only one cooling oil supply passage 55 is shown, but the cooling oil supply passages 55 may be provided at positions corresponding to a plurality (for example, five) of recesses on the outer peripheral surface of the inner rotor 44, respectively.

[0087] FIGS. 12(a) to (d) respectively correspond to FIGS. 11(a) to (d) described above. Similar to FIGS. 2, 4, 6, 8, and 10 described above, the flow of the cooling oil is indicated by arrows. As shown in FIG. 12, in the motor 1 of the present embodiment, the cooling oil circulates in the same manner as the motor 1 of the third embodiment described above, and heat exchange is performed with each coil 6b of the stator 6, whereby each coil 6b can be effectively cooled.

[0088] Also, in the motor 1 of the present embodiment, as shown in FIGS. 12(b) and (d), the cooling oil is introduced through the cooling oil introduction passage 53 of the support portion 43b of the relative rotating member 43, and the introduced cooling oil flows out to the outside in the radial direction of the inner rotor 44 through the cooling oil supply port 54 of the support portion 43b and the cooling oil supply passage 55 of the inner rotor 44. More specifically, as shown in FIG. 12(d), the cooling oil flowing out from the cooling oil supply passage 55 of the inner rotor 44 is supplied between the two rotors 44 and 42 immediately before the inner rotor 44 and the outer rotor portion 42 mesh with each other.

[0089] As described above, according to the present embodiment, the cooling oil introduced into the cooling oil introduction passage 53 of the support portion 43b of the relative rotation member 43 is supplied between the inner rotor 44 and the outer rotor portion 42 as described above, whereby a lubricating oil film is formed on the tooth surfaces of the meshing portions of the inner rotor 44 and the outer rotor portion 42. As a result, smooth meshing of both rotors 44 and 42 can be achieved, and the temperature rise of the meshing portion can be effectively suppressed. As a result, stable pump operation of the cooling pump 7 can be ensured by the rotation of the inner rotor 44 and the outer rotor portion 42.

[0090] Note that the present invention is not limited to the above-described embodiments, and can be implemented in various modes. For example, it is also possible to provide a plurality of fins for promoting heat exchange with the outside air on at least one of the first cooling oil pipe 27 and the second cooling oil pipe 28 in each embodiment. Further, in each embodiment, cooling oil is used as the refrigerant, but it is also possible to use other appropriate liquids or gases instead. Furthermore, in each embodiment, the cooling structure of the rotating machine of the present invention has been described when applied to the motor 1 that drives the rotating blades of the drone, but it can also be applied to other rotating machines, for example, a motor that drives the wheels of an electric vehicle.

[0091] Also, the detailed configurations of the motor 1, the shaft 3, the upper and lower rotors 4 and 5, the stator 6, the cooling pump 7, and the housing 8 shown in the embodiment are merely examples, and can be appropriately changed within the scope of the gist of the present invention.

Explanation of Reference Numerals

[0092] 1 Motor (Rotating Machine) 2 Rotating Blade 3 Shaft (Rotating Shaft) 4 Upper Rotor (Rotor) 5 Lower Rotor (Rotor) 6 Stator 6a Stator Core 6b Coil 7 Cooling Pump 8 Housing 21 Inner rotor (drive gear) 22 Outer rotor (driven gear) 23 Outer rotor holding part 24a Suction port 24b Discharge port 25 Cooling oil storage chamber 25a Suction chamber 25b Discharge chamber 26 Partition wall 27 First cooling oil pipe (refrigerant pipe) 28 Second cooling oil pipe (refrigerant pipe) 29 Pump cover 29a Through hole of pump cover 29b Discharge port of pump cover 31 Cooling oil guide flow path (refrigerant guide flow path) 31a First guide flow path 31b Second guide flow path 41 Hole part in shaft 41a Ceiling surface of hole part (rear wall) 42 Outer rotor part (drive gear) 43 Relative rotating member 43a Main body part 43b Support part 43c Guide flow path (third guide flow path) 44 Inner rotor (driven gear) 44a Inner peripheral surface of inner rotor 47 Cooling oil temporary storage part (refrigerant temporary storage part) 48 Guide flow path (fourth guide flow path) 51 Upper bearing (bearing) 52 Lower bearing (bearing) 53 Cooling oil introduction flow path (refrigerant introduction flow path) 54 Cooling oil supply port (refrigerant supply port) 55 Cooling oil supply flow path (refrigerant supply flow path) V Vertical axis line (predetermined axis line) E Eccentric axis line

Claims

1. A cooling structure for a rotary machine having a rotary shaft that extends along a predetermined axis and rotates about the axis, the cooling structure cooling the rotary machine during its operation, in the housing of the rotary machine, a cooling pump is provided that is disposed on the axis and operates by rotating integrally with the rotary shaft to circulate a refrigerant for cooling the rotary machine, the cooling pump is configured to be rotatable about the axis and includes a drive gear that rotates integrally with the rotary shaft, a driven gear that meshes with the drive gear and rotates as the drive gear rotates, A cooling structure for a rotary machine, characterized by comprising:

2. The rotary machine further includes a rotor that can rotate integrally with the rotary shaft with the rotary shaft passing therethrough, and a stator that is disposed at a predetermined interval from the rotor in the axial direction, The cooling structure for a rotary machine according to claim 1, further comprising a refrigerant pipe provided so as to be exposed to the outside from the housing and through which the refrigerant flows when circulating the refrigerant between the cooling pump and the stator.

3. The cooling pump is an internal gear pump, the drive gear is constituted by an inner rotor having a plurality of teeth along its outer peripheral surface, The cooling structure for a rotary machine according to claim 2, wherein the driven gear is formed in a ring shape surrounding the inner rotor and is constituted by an outer rotor having a plurality of teeth with a larger number of teeth than the inner rotor along its inner peripheral surface.

4. The housing has, inside thereof, an outer rotor holding portion that rotatably holds the outer rotor about an eccentric axis that is parallel to the axis and displaced in the radial direction, The cooling structure for a rotary machine according to claim 3, wherein an inlet for sucking the refrigerant and an outlet for discharging the refrigerant are provided on the outer rotor holding portion on the side opposite to the rotary shaft in the axial direction.

5. The rotary shaft has a refrigerant guiding flow path that guides the refrigerant discharged from the cooling pump through the rotary shaft to the stator. The cooling structure for a rotary machine according to claim 3.

6. The refrigerant guiding flow path includes a first guiding flow path that extends along the axis for a predetermined length and has one end opening to the cooling pump side, a second guiding flow path that communicates the other end of the first guiding flow path with the stator and extends along the radial direction of the axis, ​ The cooling structure of the rotating machine according to claim 5, characterized by having

7. The housing has, inside thereof, an outer rotor holding portion that rotatably holds the outer rotor about an eccentric axis that is parallel to the axis and displaced in the radial direction. The outer rotor holding portion is provided with a suction port for sucking the refrigerant on the side opposite to the rotating shaft in the axial direction, and a discharge port for discharging the refrigerant on the rotating shaft side in the axial direction, and the discharge port is connected to the one end portion of the first guide flow path. The cooling structure of the rotating machine according to claim 6, characterized by this.

8. The rotating shaft has, inside thereof, a hole portion that extends along the axis for a predetermined length and has a predetermined diameter and opens inward of the housing. A relative rotating member that is rotatable relative to the rotating shaft about the axis is provided in the hole portion. The cooling pump is an internal gear pump. The drive gear is composed of an outer rotor portion having a plurality of teeth along the inner peripheral surface of the opening in the hole portion of the rotating shaft. The driven gear is rotatably supported by the relative rotating member and is composed of an inner rotor having a plurality of teeth with a smaller number of teeth than the outer rotor portion along the outer peripheral surface. The relative rotating member has a third guide flow path that penetrates along the axis and guides the refrigerant to a refrigerant temporary storage portion that is provided between the back wall of the hole portion and the relative rotating member from the inner rotor side and temporarily stores the refrigerant. The rotating shaft is provided with a fourth guide flow path that communicates the refrigerant temporary storage portion with the stator and extends along the radial direction of the axis. The cooling structure of the rotating machine according to claim 2, characterized by this.

9. The relative rotating member has a main body portion formed in a columnar shape extending along the axis and having the third guide flow path, and a support portion that protrudes from the main body portion toward the opening side of the hole portion and rotatably supports the inner rotor about an eccentric axis displaced in the radial direction from the axis. The cooling structure of the rotating machine according to claim 8, characterized by having this.

10. The inner rotor has a state where the support portion is loosely inserted through the center portion thereof. In a rotary machine cooling structure according to claim 9, a bearing for rotatably holding the inner rotor while supporting the inner rotor in the length direction of the support portion is provided on one side and / or the other side in the length direction of the support portion in the inner rotor.

11. The support portion has a refrigerant introduction flow path for introducing refrigerant into the interior from its tip, and a refrigerant supply port that is continuous with the refrigerant introduction flow path and opens to the outside in the radial direction of the support portion, and supplies the refrigerant introduced into the refrigerant introduction flow path to the gap between the support portion and the inner rotor. A rotary machine cooling structure according to claim 10, characterized by having the above.

12. The inner rotor has a refrigerant supply flow path that penetrates in the radial direction thereof and further supplies the refrigerant supplied from the refrigerant supply port to the meshing portion between the inner rotor and the outer rotor portion. A rotary machine cooling structure according to claim 11, characterized by having the above.

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