Patent ID: 12196217

DETAILED DESCRIPTION OF EMBODIMENTS

The following will describe a first embodiment and a second embodiment of the present disclosure in detail with reference to the accompanying drawings. A turbo fluid machine according to a first embodiment and a second embodiment is mounted to a fuel cell vehicle (not illustrated), and connected to a fuel cell300illustrated inFIG.1. The turbo fluid machine according to the first embodiment and the second embodiment cooperates with the fuel cell300to form a fuel cell system500.

First Embodiment

As illustrated inFIG.1, the turbo fluid machine according to the first embodiment includes a housing1, an electric motor3, a drive shaft5, an impeller7, a turbine9, a first seal ring61, and a second seal ring63. In this embodiment, the first seal ring61and the second seal ring63cooperate to serve as the sealing member of the present disclosure as an example. The sealing member of the present disclosure includes a first sealing member and a second sealing member. Specifically, in this embodiment, the first seal ring61and the second seal ring63respectively serve as the first sealing member and the second sealing member of the present disclosure as an example.

In the embodiments, the front-rear direction and the up-down direction of the turbo fluid machine are indicated by the solid arrows inFIGS.1-3. The front-rear direction serves as the axial direction of the drive shaft of the present disclosure as an example. The up-down direction is a direction in which the gravity acts on the housing1, so that the gravity acts on the housing1from top to bottom. The front-rear direction and the up-down direction are at right angles to each other. The turbo fluid machine according to the embodiments is mounted to the fuel cell vehicle such that an axial direction of the drive shaft5corresponds to the front-rear direction of the turbo fluid machine. Accordingly, the gravity acts on the turbo fluid machine, including the housing1, in a direction perpendicular to the axial direction of the drive shaft5. The turbo fluid machine may be mounted at various postures depending on the fuel cell vehicle.

The housing1is made of aluminum alloy. The housing1includes a motor housing10, a first plate11, a second plate12, a third plate13, a compressor housing14, and a turbine housing15.

The motor housing10includes an end wall10aand a peripheral wall10b. The end wall10ais located at a rear end of the motor housing10, and extends in a radial direction of the motor housing10, i.e., a radial direction of the housing1. The end wall10ahas opposite surfaces, i.e., a first surface101and a second surface102, which are oriented frontward and rearward, respectively. The second surface102forms the rear surface of the motor housing10.

The peripheral wall10bis integrally formed with the end wall10a, has a cylindrical shape, and extends frontward from the end wall10a. The peripheral wall10bhas an opening at a front end thereof. The end wall10aand the peripheral wall10bcooperate to form the bottomed-cylindrical motor housing10. The peripheral wall10bof the motor housing10has a supply passage31. The supply passage31extends in the radial direction of the housing1, and is opened on an outer peripheral surface103and an inner peripheral surface104of the peripheral wall10b. The peripheral wall10bhas a flange portion10cat a front end thereof. The flange portion10cextends from the peripheral wall10bin the radial direction of the motor housing10.

The first plate11is located in front of the motor housing10. The first plate11has a first front surface11aand a first rear surface11brespectively on the front side and the rear side of the first plate11. The first plate11is connected to the flange portion10cwith the first rear surface11bcontacting the flange portion10c. The opening of the peripheral wall10bis closed by the first plate11. The end wall10aand the peripheral wall10bcooperate with the first rear surface11bto define a motor chamber30in the motor housing10. The motor chamber30is communicated with the supply passage31. The motor chamber30is communicated with the outside of the housing1through the supply passage31.

The first plate11includes a first boss11c, a first recess11d, and a first through hole11e. The first boss11chas a cylindrical shape and extends rearward from the first rear surface11binto the motor chamber30. A first radial bearing21ais disposed inside the first boss11c.

The first recess11dis recessed rearward from the first front surface11a. A first thrust bearing23aand a second thrust bearing23bare disposed inside the first recess11d. The first through hole11eis located at a center portion of the first plate11and formed through the first plate11in the front-rear direction. A front end of the first through hole11eis communicated with the first recess11d, and a rear end of the first through hole11eis communicated with the first boss11c. The first boss11c, the first recess11d, and the first through hole11eare formed coaxially with each other.

The end wall10aof the motor housing10includes a second boss10d, a second through hole10e, and a connecting passage33. The second boss10dhas a cylindrical shape and extends frontward from the first surface101into the motor chamber30. A second radial bearing21bis disposed inside the second boss10d. In this embodiment, the first radial bearing21aand the second radial bearing21bare gas bearings. However, the first radial bearing21aand the second radial bearing21bmay be any bearings other than gas bearings.

The second through hole10eis located at a center portion of the end wall10aand formed through the end wall10ain the front-rear direction. The second through hole10eis communicated with the second boss10dat a front end of the second through hole10e. The second boss10dand the second through hole10eare formed coaxially with the first boss11c, the first recess11d, and the first through hole11e.

The connecting passage33is formed through the end wall10ain the front-rear direction. The connecting passage33is communicated with the motor chamber30. Specifically, the connecting passage33is communicated with the rear portion of the motor chamber30.

The second plate12is located in front of the first plate11. The second plate12has a second front surface12aand a second rear surface12brespectively on the front side and the rear side of the second plate12. The second plate12is connected to the first plate11with the second rear surface12bcontacting the first front surface11a.

The second plate12includes a second recess12cand a third through hole12d. The second recess12cis recessed rearward from the second front surface12a. A diameter of the second recess12cis smaller than a diameter of the first recess11d. A front end of the second recess12cis communicated with an impeller chamber27a, which is described later. A third seal ring25made of metal is disposed inside the second recess12c.

The third through hole12dis located at a center portion of the second plate12and formed through the second plate12in the front-rear direction. A front end of the third through hole12dis communicated with the second recess12c, and a rear end of the third through hole12dis communicated with the first recess11d. The second recess12cand the third through hole12dare formed coaxially with the first boss11c, the first recess11d, and the first through hole11e.

The first boss11c, the first recess11d, the first through hole11e, the second recess12c, and the third through hole12dcooperate to form a first shaft hole35. The first shaft hole35is located between the impeller chamber27aand the motor chamber30in the housing1, and communicated with the impeller chamber27aand the motor chamber30.

The third plate13is located behind the motor housing10. The third plate13has a third front surface13aand a third rear surface13brespectively on the front side and the rear side of the third plate13. The third plate13is connected to the motor housing10with the third front surface13acontacting the second surface102of the end wall10a.

The third plate13has a fourth through hole13c, a water discharge passage13d, and a plate connecting passage13e. The fourth through hole13cis located at a center portion of the third plate13and formed through the third plate13in the front-rear direction. The fourth through hole13cis formed coaxially with the second through hole10e.

As illustrated inFIG.2, the fourth through hole13chas a first hole portion131and a second hole portion132. The first hole portion131forms the front portion of the fourth through hole13c. The first hole portion131has the same diameter as the second through hole10ehas, and is communicated with the second through hole10e. The second hole portion132is located behind the first hole portion131and forms the rear portion of the fourth through hole13c. The second hole portion132is formed coaxially with the first hole portion131, and a diameter of the second hole portion132is smaller than a diameter of the first hole portion131. The second hole portion132is communicated with a turbine chamber29a, which is described later. The fourth through hole13cis located between the second through hole10eand the turbine chamber29aand communicated with the second through hole10eand the turbine chamber29a.

The second boss10d, the second through hole10e, and the fourth through hole13ccooperate to form a second shaft hole37. The second shaft hole37is located between the motor chamber30and the turbine chamber29ain the housing1, and communicated with the motor chamber30and the turbine chamber29a.

The water discharge passage13dis communicated with the first hole portion131, extends through the third plate13in the radial direction of the housing1, and is opened on an outer peripheral surface130of the third plate13. The second shaft hole37is communicated with the outside of the housing1through the water discharge passage13d.

The plate connecting passage13eextends frontward through the third plate13, and a rear end of the plate connecting passage13eis connected to the water discharge passage13d. Further, a front end of the plate connecting passage13eis opened on the third front surface13aof the third plate13. Since the third plate13is connected to the motor housing10, the plate connecting passage13eis connected to the connecting passage33. Accordingly, the connecting passage33is communicated with the water discharge passage13dthrough the plate connecting passage13e.

As illustrated inFIG.1, the compressor housing14is located in front of the second plate12. The compressor housing14has a cylindrical shape, and is connected to the second plate12while contacting the second front surface12aof the second plate12. The compressor housing14forms a front end portion of the housing1.

The compressor housing14has a first inlet14aand a first outlet14b. The first inlet14ais formed coaxially with the first shaft hole35, and extends through the compressor housing14in the front-rear direction. A front end of the first inlet14ais opened on a front surface140of the compressor housing14. The first outlet14bextends through the compressor housing14in the radial direction, and is opened on an outer peripheral surface141of the compressor housing14.

The impeller chamber27a, the discharge chamber27b, and a first diffuser passage27care formed between the compressor housing14and the second front surface12a. The impeller chamber27ais communicated with the first inlet14a. The discharge chamber27bextends about the axis of the first inlet14aaround the impeller chamber27a. The discharge chamber27bis communicated with the first outlet14b. The impeller chamber27ais communicated with the discharge chamber27bthrough the first diffuser passage27c. The impeller chamber27ais communicated with the first outlet14bthrough the first diffuser passage27cand the discharge chamber27b.

The turbine housing15is located behind the third plate13. The turbine housing15has a cylindrical shape, and is connected to the third plate13while contacting the third rear surface13bof the third plate13. The turbine housing15forms a rear end portion of the housing1.

The turbine housing15has a second inlet15aand a second outlet15b. The second inlet15aextends through the turbine housing15in the radial direction, and is opened on an outer peripheral surface151of the turbine housing15. The second outlet15bis formed coaxially with the second shaft hole37, and extends through the turbine housing15in the front-rear direction. A rear end of the second outlet15bis opened on a rear surface150of the turbine housing15.

The turbine chamber29a, a suction chamber29b, and a second diffuser passage29care formed between the turbine housing15and the third rear surface13b. The turbine chamber29ais communicated with the second outlet15b. The suction chamber29bextends about the axis of the second outlet15baround the turbine chamber29a. The suction chamber29bis communicated with the second inlet15a. The turbine chamber29ais communicated with the suction chamber29bthrough the second diffuser passage29c. The turbine chamber29ais communicated with the second inlet15athrough the second diffuser passage29cand the suction chamber29b.

In the housing1, the impeller chamber27ais located away from the turbine chamber29ain the front-rear direction, and the motor chamber30is located between the impeller chamber27aand the turbine chamber29a.

The first inlet14ais connected to a pipe41. Cathode gas containing oxygen is introduced from the outside of the housing1into the first inlet14athrough the pipe41. Furthermore, the first outlet14bis connected to one end of a pipe43. The other end of the pipe43is connected to the fuel cell300. Accordingly, the discharge chamber27bis connected to the fuel cell300. The pipe43is connected to one end of the pipe45. The other end of the pipe45is connected to the supply passage31. The pipe45is provided with an intercooler400. The intercooler400is available in the market.

The fuel cell300is connected to one end of a pipe47. The other end of the pipe47is connected to the second inlet15a. Accordingly, the fuel cell300is connected to the suction chamber29b. The second outlet15bis connected to a pipe49.

The electric motor3is accommodated in the motor chamber30. The electric motor3includes a stator3aand a rotor3b. The stator3ahas a cylindrical shape, extends in the front-rear direction, and is fixed to an inner peripheral surface104of the peripheral wall10b. The stator3ais connected to a power supply unit (not illustrated) that is disposed outside the housing1. The rotor3bhas a cylindrical shape and extends in the front-rear direction, and a diameter of the rotor3bis smaller than a diameter of the stator3a. The rotor3bis disposed in the stator3a.

The drive shaft5includes a drive shaft body51and a seal carrier53. The drive shaft body51is made of metal. The drive shaft body51has a solid cylindrical shape and extends in the front-rear direction. The drive shaft body51has a first shaft portion51a, a second shaft portion51b, a third shaft portion51c, and a fourth shaft portion51dthat are arranged from front to rear in this order. The first shaft portion51a, the second shaft portion51b, the third shaft portion51c, and the fourth shaft portion51dare formed coaxially with each other.

The first shaft portion51ahas the same diameter as the fourth shaft portion51dhas. Specifically, the first shaft portion51aand the fourth shaft portion51dhave a diameter having a first length L1(seeFIG.2), which is the smallest diameter of the drive shaft body51. As illustrated inFIG.1, the second shaft portion51bhas a diameter that is larger than the diameters of the first shaft portion51aand the fourth shaft portion51d. A front end of the second shaft portion51bis connected to the first shaft portion51a. Specifically, the second shaft portion51bhas a diameter having a second length L2, which is larger than the first length L1of the diameters of the first shaft portion51aand the fourth shaft portion51d(seeFIG.2). The third shaft portion51chas a diameter having a third length L3that is larger than the second length L2of the diameter of the second shaft portion51b. The diameter of the third shaft portion51cis the largest diameter of the drive shaft body51. As illustrated inFIG.1, a front end and a rear end of the third shaft portion51care respectively connected to the second shaft portion51band the fourth shaft portion51d.

As illustrated inFIG.2, the seal carrier53is made of metal and has a cylindrical shape. The seal carrier53is fixed to the fourth shaft portion51dby press-fitting. The seal carrier53is in contact with the rear end of the third shaft portion51c. Accordingly, the seal carrier53is integral with the drive shaft body51.

The seal carrier53has a first diameter portion53a, a second diameter portion53b, and a step portion53c. The first diameter portion53a, the second diameter portion53b, and the step portion53care formed coaxially with each other. The first diameter portion53a, the second diameter portion53b, and the step portion53care formed coaxially with the drive shaft body51since the seal carrier53is fixed to the fourth shaft portion51d.

The first diameter portion53aforms a front portion of the seal carrier53. The first diameter portion53ahas the same diameter as the third shaft portion51cof the drive shaft body51has, that is, the first diameter portion53ahas a diameter having the third length L3. Accordingly, the diameters of the first diameter portion53aand the third shaft portion51care the largest diameter of the drive shaft5. The first diameter portion53ahas a first ring groove55ain an outer peripheral surface of the first diameter portion53a.

The second diameter portion53bforms a rear portion of the seal carrier53, and is located between the first diameter portion53aand the turbine chamber29ain the axial direction. A diameter of the second diameter portion53bis smaller than the diameter of the first diameter portion53a. The second diameter portion53bhas the same diameter as the second shaft portion51bof the drive shaft body51has, in other words, the second diameter portion53bhas a diameter having the second length L2. The second diameter portion53bhas a second ring groove55bin an outer peripheral surface of the second diameter portion53b.

The third length L3is smaller than a length of an inner diameter of the first hole portion131of the fourth through hole13c, and larger than a length of an inner diameter of the second hole portion132. The second length L2is smaller than a length of the inner diameter of the second hole portion132. Accordingly, the diameters of the third shaft portion51cand the first diameter portion53aare smaller than the diameter of the first hole portion131, and larger than the diameter of the second hole portion132. The diameter of the second diameter portion53bis smaller than the diameter of the second hole portion132.

The step portion53cis located between the first diameter portion53aand the second diameter portion53b. The step portion53cextends in a radial direction of the seal carrier53, and is continuous with the first diameter portion53aand the second diameter portion53b.

As illustrated inFIG.1, the drive shaft5is disposed in the housing1and inserted through the first shaft hole35and the second shaft hole37. In the motor chamber30, the third shaft portion51cof the drive shaft body51of the drive shaft5is inserted through and fixed to the rotor3b. The third shaft portion51cis inserted through the first radial bearing21ain the first boss11c, and further inserted through the second radial bearing21bin the second boss10d. The drive shaft5is rotatable about an axis O of the drive shaft5. The axis O extends in parallel to the front-rear direction of the turbo fluid machine.

The first shaft portion51aof the drive shaft body51of the drive shaft5extends into the impeller chamber27a. The second shaft portion51bis inserted through the third seal ring25in the second recess12c. The third seal ring25is disposed between the first shaft hole35and the drive shaft5so as to seal a gap between the impeller chamber27aand the motor chamber30. In the first recess11d, the second shaft portion51bis inserted through the first thrust bearing23aand the second thrust bearing23b, and press-fitted in a support plate57. The support plate57is disposed between the first thrust bearing23aand the second thrust bearing23b. Accordingly, the support plate57cooperates with the second rear surface12bof the second plate12to hold therebetween the first thrust bearing23ain the front-rear direction, and cooperates with a wall surface of the first recess11dto hold therebetween the second thrust bearing23bin the front-rear direction.

As illustrated inFIG.1, the fourth shaft portion51dof the drive shaft body51of the drive shaft5extends into the turbine chamber29a. The rear end of the third shaft portion51cand the seal carrier53are located in the fourth through hole13c. Specifically, the rear end of the third shaft portion51cand the first diameter portion53aof the seal carrier53are located in the first hole portion131of the fourth through hole13c, and the second diameter portion53bof the seal carrier53is located in the second hole portion132.

The impeller7is accommodated in the impeller chamber27a. The impeller7is fixed to the first shaft portion51aof the drive shaft body51of the drive shaft5. The turbine9is accommodated in the turbine chamber29a. The turbine9is fixed to the fourth shaft portion51dof the drive shaft body51. The drive shaft5connects the electric motor3, the impeller7, and the turbine9. The impeller7rotates about the axis O of the drive shaft5in the impeller chamber27awith the rotation of the drive shaft5about the axis O of the drive shaft5. Similarly, the turbine9rotates about the axis O of the drive shaft5in the turbine chamber29awith the rotation of the drive shaft5about the axis O of the drive shaft5.

The first seal ring61and the second seal ring63are made of metal. As illustrated inFIG.2, a diameter of the second seal ring63is smaller than a diameter of the first seal ring61. The first seal ring61is held in the first ring groove55a, and disposed in the first diameter portion53aof the seal carrier53. The second seal ring63is held in the second ring groove55b, and disposed in the second diameter portion53bof the seal carrier53. Accordingly, the first seal ring61is located away from the second seal ring63in the seal carrier53, i.e., the drive shaft5in the front-rear direction. Specifically, the second seal ring63is located behind the first seal ring61.

The first seal ring61and the second seal ring63are located in the fourth through hole13cwith the seal carrier53since the seal carrier53is located in the fourth through hole13c. The first seal ring61is located between the first hole portion131and the first diameter portion53a. The second seal ring63is located between the second hole portion132and the second diameter portion53b. The first seal ring61and the second seal ring63are disposed between the second shaft hole37and the drive shaft5to seal a gap between the motor chamber30and the turbine chamber29a.

The seal carrier53(i.e., the drive shaft5), an inner peripheral surface of the first hole portion131and an inner peripheral surface of the second hole portion132(i.e., the second shaft hole37), the first seal ring61, and the second seal ring63cooperate to form a first reservoir S1in the second shaft hole37. The first reservoir S1serves as the reservoir of the present disclosure as an example. The first reservoir S1is communicated with the water discharge passage13d. The first reservoir S1is sealed off from the motor chamber30by the first seal ring61, and also from the turbine chamber29aby the second seal ring63.

The fuel cell300illustrated inFIG.1is available in the market, and includes a plurality of fuel cells. The fuel cell300generates power by a chemical reaction of cathode gas with anode gas.

In this turbo fluid machine, power is supplied from the power supply unit to the electric motor3to operate the electric motor3, and the drive shaft5rotates about the axis O of the drive shaft5. Thus, the impeller7rotates about the axis O of the drive shaft5in the impeller chamber27a.

With the rotation of the electric motor3, the impeller7compresses the cathode gas introduced into the impeller chamber27afrom the first inlet14a. The cathode gas compressed by the impeller7is discharged to the pipe43from the first outlet14b. The cathode gas then flows through the pipe43, and is supplied to the fuel cell300. The fuel cell300thus generates power.

Part of the cathode gas flows from the pipe43into the pipe45and is cooled by the intercooler400, and the cathode gas is then supplied to the motor chamber30through the supply passage31. Accordingly, the pressure in the motor chamber30becomes higher than the pressure in the first reservoir S1and the pressure in the turbine chamber29a.

The exhaust containing the cathode gas used in the power generation is discharged from the fuel cell300, and introduced into the turbine chamber29athrough the pipe47, the second inlet15a, and the suction chamber29b. The exhaust from the fuel cell300rotates the turbine9about the axis O of the drive shaft5in the turbine chamber29a. Accordingly, the turbine9assists the electric motor3to cause the drive shaft5to rotate about the axis O. The exhaust introduced into the turbine chamber29ahas a pressure lower than a pressure of the cathode gas in the pipe43, i.e., a pressure of the cathode gas compressed by the impeller7. The exhaust introduced into the turbine chamber29ais discharged, by the turbine9rotating about the axis O of the drive shaft5, to the outside of the housing1through the second outlet15band the pipe49.

The exhaust from the fuel cell300contains water produced during the power generation by the fuel cell300. The produced water is discharged with the exhaust from the second outlet15binto the pipe49, but part of the produced water may be stored in the turbine chamber29a.

In this turbo fluid machine, the seal carrier53has the first seal ring61and the second seal ring63, and the second seal ring63is located behind the first seal ring61, that is, the second seal ring63is located away from the first seal ring61and between the first seal ring61and the turbine chamber29a.

This configuration of the turbo fluid machine prevents the produced water from directly flowing into the motor chamber30and stores the water in the first reservoir S1, even if the water flows through a gap between the second hole portion132of the fourth through hole13cand the second seal ring63from the turbine chamber29aas indicated by a dashed arrow inFIG.2. If the water is to flow from the first reservoir S1toward the motor chamber30, the water needs to flow over the step portion53cand through a gap between the first hole portion131of the fourth through hole13cand the first seal ring61. Accordingly, the water is unlikely to flow into the motor chamber30from the first reservoir S1. Furthermore, the pressure in the motor chamber30is higher than the pressure in the first reservoir S1and the pressure in the turbine chamber29asince part of the cathode gas compressed by the impeller7is supplied to the motor chamber30through the supply passage31. Accordingly, the water is further unlikely to flow into the motor chamber30from the first reservoir S1.

The produced water in the first reservoir S1is discharged to the outside of the third plate13, i.e., the outside of the housing1, through the water discharge passage13d. Accordingly, this turbo fluid machine suitably prevents the produced water from flowing into the motor chamber30from the turbine chamber29athrough the second shaft hole37.

Therefore, the turbo fluid machine according to the first embodiment is capable of suitably preventing short circuit in the electric motor3due to the water contained the exhaust from the fuel cell300.

Particularly, this turbo fluid machine has the connecting passage33in the end wall10aof the motor housing10, and the connecting passage33is communicated with the water discharge passage13dthrough the plate connecting passage13eof the third plate13. Accordingly, even if the water flows through the gap between the first hole portion131of the fourth through hole13cand the first seal ring61and flows into the motor chamber30through the second through hole10eand the second boss10d, the water is discharged easily to the outside of the housing1from the motor chamber30through the connecting passage33, the plate connecting passage13e, and the water discharge passage13dby the pressure difference between the inside of the motor chamber30and the outside of the housing1without reaching the electric motor3(as indicated by the dashed arrow inFIG.2). In this regard, this turbo fluid machine also suitably prevents short circuit in the electric motor3due to the produced water contained in the cathode gas.

Second Embodiment

As illustrated inFIG.3, in the turbo fluid machine according to a second embodiment, the seal carrier53(i.e., the drive shaft5), the inner peripheral surface of the first hole portion131and the inner peripheral surface of the second hole portion132(i.e., the second shaft hole37), the first seal ring61, and the second seal ring63cooperate to form a second reservoir S2. The second reservoir S2serves as the reservoir of the present disclosure as an example.

The second reservoir S2includes a reservoir body S21and a groove S22. The reservoir body S21has a size equal to the size of the first reservoir S1of the turbo fluid machine according to the first embodiment, and the reservoir body S21is sealed off from the motor chamber30by the first seal ring61and also from the turbine chamber29aby the second seal ring63.

The groove S22is formed in the first hole portion131(i.e., the second shaft hole37). The groove S22is located below the axis O in the first hole portion131, and rectangularly recessed downward from the inner peripheral surface of the first hole portion131in the radial direction of the drive shaft5. That is, the groove S22is recessed in a direction in which the gravity acts on the turbo fluid machine with the turbo fluid machine mounted to the fuel cell vehicle. The groove S22faces the reservoir body S21and is communicated with the reservoir body S21. The groove S22is further communicated with the water discharge passage13d. The groove S22may be formed in the inner peripheral surface of the first hole portion131and extend in a circumferential direction of the drive shaft5so as to have a ring shape. It is to be noted that, other components of the turbo fluid machine according to the second embodiment are the same as those of the turbo fluid machine according to the first embodiment, and components of the turbo fluid machine according to the second embodiment that correspond to those of the turbo fluid machine according to the first embodiment are designated by the same reference numerals and will not be further elaborated here.

In this turbo fluid machine, even if the water flows from the turbine chamber29ainto the second reservoir S2through the gap between the second hole portion132of the fourth through hole13cand the second seal ring63, the water flows from the reservoir body S21of the second reservoir S2to the groove S22by the gravity acting on the housing1, and is stored in the groove S22. The water stored in the groove S22is then discharged to the outside of the housing1through the water discharge passage13d.

Since the second reservoir S2includes the reservoir body S21and the groove S22, the second reservoir S2of this turbo fluid machine is capable of storing a large amount of produced water. This configuration suppresses the overflow of the water from the second reservoir S2even if a large amount of the water flows into the second reservoir S2from the turbine chamber29a. Further, the water is stored in the groove S22, so that the water is unlikely to flow through the gap between the first hole portion131and the first seal ring61. Accordingly, in this turbo fluid machine, the water in the second reservoir S2is unlikely to flow into the motor chamber30. Other advantageous effects of this turbo fluid machine are the same as those of the turbo fluid machine according to the first embodiment.

Although the present disclosure has been described by the first and second embodiments, the present disclosure is not limited to those embodiments, and may be modified within the scope of the present disclosure.

For example, according to the first embodiment and the second embodiment, the drive shaft5of the turbo fluid machine includes the drive shaft body51and the seal carrier53. However, the configuration of the drive shaft5is not limited thereto. The drive shaft5may only include the drive shaft body51, and the third shaft portion51cand the fourth shaft portion51dmay be provided with the first seal ring61and the second seal ring63, respectively.

According to the first embodiment and the second embodiment, in the turbo fluid machine, the diameter of the second seal ring63is smaller than the diameter of the first seal ring61, but the configurations of the first seal ring61and the second seal ring63are not limited thereto. The diameter of the second seal ring63may be equal to the diameter of the first seal ring61.

Furthermore, the gap between the motor chamber30and the turbine chamber29amay be sealed by any sealing member, such as other seal ring, in addition to the first seal ring61and the second seal ring63.

The supply passage31, the connecting passage33, and the plate connecting passage13emay be omitted.

According to the first embodiment and the second embodiment, the water discharge passage13dof the turbo fluid machine is opened on the outer peripheral surface130of the third plate13. However, the configuration of the water discharge passage13dis not limited thereto. The water discharge passage13dmay be opened to the second outlet15bso as to be communicated with the outside of the housing1. In this configuration, the produced water flows through the water discharge passage13d, and is discharged from the second outlet15bto the outside of the housing1.

The present disclosure is applicable to a fuel cell vehicle, a fuel cell system, and the like.