Turbo fluid machine

Abstract

To provide a turbo type fluid machine capable of suitably preventing short circuit of an electric motor caused by generation water included in exhaust gas from a fuel cell.SOLUTION: In a turbo type fluid machine, a first seal ring 61 and a second seal ring 63 are provided between a second shaft hole 37 and a drive shaft 5. The first seal ring 61 and the second seal ring 63 seal a space between a motor chamber 30 and a turbine chamber 29a. The second seal ring 63 is separated to the turbine chamber 29a side in the axial direction of the drive shaft 5 from the first seal ring 61. In the turbo type fluid machine, a first storage chamber S1 is formed by the drive shaft 5, the second shaft hole 37, the first seal ring 61 and the second seal ring 63. A drain passage 13d in communication with the first storage chamber S1 and discharging generation water in the first storage chamber S1 to outside of a housing 1 is formed in the housing 1.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a turbo-type fluid machine.

Background Art

[0002] Patent Document 1 discloses a conventional turbo-type fluid machine. This turbo-type fluid machine includes a housing, an electric motor, an impeller, a turbine, a drive shaft, and a sealing member.

[0003] The housing is formed with an impeller chamber, a turbine chamber, a motor chamber, a first shaft hole, and a second shaft hole. The impeller chamber and the turbine chamber are arranged apart from each other in the axial direction of the drive shaft. The motor chamber is located between the impeller chamber and the turbine chamber. The first shaft hole is located between the impeller chamber and the motor chamber and communicates with the impeller chamber and the motor chamber. The second shaft hole is located between the motor chamber and the turbine chamber and communicates with the motor chamber and the turbine chamber. The electric motor is housed in the motor chamber. The impeller is housed in the impeller chamber. The turbine is housed in the turbine chamber. The drive shaft is supported by the first shaft hole and the second shaft hole and extends in the axial direction to connect the electric motor, the impeller, and the turbine. One sealing member is provided between the second shaft hole and the drive shaft to seal between the motor chamber and the turbine chamber.

[0004] This turbo-type fluid machine is connected to a fuel cell. Then, when the impeller rotates by the electric motor of this turbo-type fluid machine, the impeller compresses the cathode gas supplied to the fuel cell. Further, the exhaust gas from the fuel cell is introduced into the turbine chamber. Thereby, the turbine rotates in the turbine chamber.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] By the way, the exhaust gas from the fuel cell may contain generated water produced during power generation in the fuel cell. Therefore, if this generated water enters the motor chamber through the second shaft hole, there is a risk of a short circuit occurring in the electric motor. In this regard, in the above conventional turbo-type fluid machine, a sealing member is used to prevent the generated water from entering the motor chamber through the second shaft hole. However, since the sealing member cannot completely seal the space between the motor chamber and the turbine chamber, a single sealing member alone cannot sufficiently prevent the generated water from entering the motor chamber. For this reason, in this turbo-type fluid machine, a short circuit of the electric motor caused by the generated water cannot be suitably prevented.

[0007] The present invention has been made in view of the above conventional situation, and an object to be solved is to provide a turbo-type fluid machine capable of suitably preventing a short circuit of an electric motor caused by generated water contained in the exhaust gas from a fuel cell.

Means for Solving the Problems

[0008] The turbo-type fluid machine of the present invention includes an impeller chamber, a turbine chamber, a motor chamber located between the impeller chamber and the turbine chamber, a first shaft hole located between the impeller chamber and the motor chamber and communicating with the impeller chamber and the motor chamber, and a second shaft hole located between the motor chamber and the turbine chamber and communicating with the motor chamber and the turbine chamber, and a housing in which these are formed, an electric motor housed in the motor chamber, an impeller housed in the impeller chamber and compressing the cathode gas supplied to the fuel cell by the rotation of the electric motor, a turbine housed in the turbine chamber and rotated by the exhaust gas from the fuel cell, a drive shaft inserted through the first shaft hole and the second shaft hole and connecting the electric motor, the impeller, and the turbine, A turbo-type fluid machine provided with a sealing member that is provided between the second shaft hole and the drive shaft and seals between the motor chamber and the turbine chamber, The sealing member has a first sealing member and a second sealing member that is spaced apart from the first sealing member toward the turbine chamber side in the axial direction of the drive shaft, A storage chamber capable of storing the generated water contained in the exhaust gas is formed by the drive shaft, the second shaft hole, the first sealing member, and the second sealing member, The housing is characterized in that a drainage channel is formed that communicates with the storage chamber and discharges the generated water in the storage chamber to the outside of the housing.

[0009] In the turbo-type fluid machine of the present invention, the first sealing member and the second sealing member are spaced apart in the axial direction of the drive shaft. For this reason, even if the generated water contained in the exhaust gas from the fuel cell flows between the second shaft hole and the second sealing member, this generated water is first stored in the storage chamber. Then, in order for the generated water in the storage chamber to flow toward the motor chamber, it has to further flow between the second shaft hole and the first sealing member. As a result, it becomes more difficult for the generated water to enter the motor chamber than in the past. Also, the generated water in the storage chamber is discharged to the outside of the housing through the drainage channel. Thus, in this turbo-type fluid machine, it is possible to suitably prevent the generated water from entering the motor chamber through the second shaft hole.

[0010] Therefore, the turbo-type fluid machine of the present invention can suitably prevent a short circuit of the electric motor caused by the generated water contained in the exhaust gas from the fuel cell.

[0011] The drive shaft may have a first diameter portion, a second diameter portion that is coaxial with the first diameter portion, is located on the turbine chamber side in the axial direction from the first diameter portion, and is formed to have a smaller diameter than the first diameter portion, and a stepped portion that is coaxial with the first diameter portion and the second diameter portion and is located between the first diameter portion and the second diameter portion. The first sealing member is provided on the first diameter portion, and the second sealing member is preferably provided on the second diameter portion and is formed to have a smaller diameter than the first sealing member. Diameter part It is preferably provided at.

[0012] In this case, the generated water that has entered the storage chamber is less likely to flow toward the first sealing member side, i.e., the motor chamber side, due to the stepped portion, and thus it is less likely to enter the motor chamber.

[0013] The storage chamber is preferably formed in the second shaft hole and has a groove portion that is recessed in the direction in which gravity acts. In this case, by suitably securing the storage chamber, the generated water that has entered the storage chamber can be stored in a large volume. Therefore, even when the amount of generated water is large, it is less likely for the generated water to enter the motor chamber through the second shaft hole.

[0014] Preferably, the housing is formed with a supply passage for supplying a part of the cathode gas compressed by the impeller into the motor chamber, and a communication passage connecting the motor chamber and the drain passage.

[0015] In this case, the cathode gas supplied into the motor chamber through the supply passage can make the pressure in the motor chamber preferably higher than that in the turbine chamber. Therefore, the generated water in the storage chamber is less likely to flow between the second shaft hole and the first sealing member and enter the motor chamber. Also, since the motor chamber is connected to the drain passage by the communication passage, even if the generated water flows between the first sealing member and enters the motor chamber, the generated water is likely to be discharged from the drain passage to the outside of the housing through the communication passage before reaching the electric motor due to the pressure difference between the inside of the motor chamber and the outside of the housing. Thereby, this turbo-type fluid machine can more preferably prevent a short circuit of the electric motor caused by the generated water contained in the exhaust gas from the fuel cell.

Advantages of the Invention

[0016] The turbo-type fluid machine of the present invention can reliably prevent a short circuit of the electric motor caused by the generated water contained in the exhaust gas from the fuel cell.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

MODE FOR CARRYING OUT THE INVENTION

[0018] Hereinafter, Examples 1 and 2 embodying the present invention will be described with reference to the drawings. The turbo-type fluid machines of Examples 1 and 2 are both mounted on a fuel cell vehicle (not shown) and are connected to the fuel cell 300 shown in FIG. 1. Thus, the turbo-type fluid machines of Examples 1 and 2, together with the fuel cell 300, constitute a fuel cell system 500.

[0019] (Example 1) As shown in FIG. 1, the turbo-type fluid machine of Example 1 includes a housing 1, an electric motor 3, a drive shaft 5, an impeller 7, a turbine 9, a first seal ring 61, and a second seal ring 63. The first seal ring 61 and the second seal ring 63 are examples of the "sealing member" in the present invention. More specifically, the first seal ring 61 is an example of the "first sealing member" in the present invention, and the second seal ring 63 is an example of the "second sealing member" in the present invention.

[0020] In this embodiment, the front-rear direction and the up-down direction of the turbo-type fluid machine are defined by the solid arrows shown in FIGS. 1 to 3. The front-rear direction is an example of the "axial direction of the drive shaft" in the present invention. The up-down direction is the direction of gravity acting on the housing 1, and gravity acts on the housing 1 from above to below. The front-rear direction and the up-down direction are orthogonal to each other. And the turbo-type fluid machine of this embodiment is mounted on the fuel cell vehicle in a posture where the axial direction of the drive shaft 5 is the front-rear direction. For this reason, with respect to the turbo-type fluid machine including the housing 1, gravity acts orthogonally to the axial direction of the drive shaft. Note that the turbo-type fluid machine can appropriately change its own posture according to the fuel cell vehicle on which it is mounted.

[0021] The housing 1 is made of an aluminum alloy. The housing 1 consists of a motor housing 10, a first plate 11, a second plate 12, a third plate 13, a compressor housing 14, and a turbine housing 15.

[0022] The motor housing 10 has an end wall 10a and a peripheral wall 10b. The end wall 10a is located at the rear end of the motor housing 10 and extends in the radial direction of the motor housing 10, that is, the radial direction of the housing 1. The end wall 10a has a first end face 101 facing forward and a second end face 102 located on the opposite side of the first end face 101 and facing rearward. The second end face 102 constitutes the rear end face of the motor housing 10.

[0023] The peripheral wall 10b is integral with the end wall 10a and extends cylindrically forward from the end wall 10a. The front of the peripheral wall 10b is open. By these end wall 10a and peripheral wall 10b, the motor housing 10 has a bottomed cylindrical shape. Further, a supply passage 31 is formed in the peripheral wall 10b. The supply passage 31 extends in the radial direction of the housing 1 and opens to the outer peripheral surface 103 and the inner peripheral surface 104 of the peripheral wall 10b. Further, a flange portion 10c is formed at the front end of the peripheral wall 10b. The flange portion 10c projects in the radial direction of the motor housing 10 more than the peripheral wall 10b.

[0024] The first plate 11 is located in front of the motor housing 10. The first plate 11 has a first front face 11a located in front and a first rear face 11b located in the rear. The first plate 11 is connected to the flange portion 10c while bringing the first rear face 11b into contact with the flange portion 10c. Thereby, the first plate 11 closes the opening of the peripheral wall 10b. Thus, an end wall 10a, a peripheral wall 10b, and a first rear face 11b partition a motor chamber 30 inside the motor housing 10. The motor chamber 30 communicates with the supply passage 31. Thereby, the motor chamber 30 communicates with the outside of the housing 1 through the supply passage 31.

[0025] The first plate 11 is formed with a first boss portion 11c, a first recessed portion 11d, and a first through hole 11e. The first boss portion 11c protrudes cylindrically rearward from the first rear surface 11b and extends into the motor chamber 30. A first radial bearing 21a is provided inside the first boss portion 11c.

[0026] The first recessed portion 11d is recessed rearward from the first front surface 11a. A first thrust bearing 23a and a second thrust bearing 23b are provided inside the first recessed portion 11d. The first through hole 11e is located at the central portion of the first plate 11 and penetrates the first plate 11 in the front-rear direction. As a result, the first through hole 11e communicates with the first recessed portion 11d at the front end and with the first boss portion 11c at the rear end. These first boss portion 11c, first recessed portion 11d, and first through hole 11e are coaxial with each other.

[0027] Also, on the end wall 10a of the motor housing 10, a second boss portion 10d, a second through hole 10e, and a communication path 33 are formed. The second boss portion 10d protrudes cylindrically forward from the first end surface 101 and extends into the motor chamber 30. A second radial bearing 21b is provided inside the second boss portion 10d. Here, gas bearings are employed as the above-described first radial bearing 21a and second radial bearing 21b. Note that bearings other than gas bearings may be employed as the first radial bearing 21a and second radial bearing 21b.

[0028] The second through hole 10e is located at the central portion of the end wall 10a and penetrates the end wall 10a in the front-rear direction. As a result, the second through hole 10e communicates with the second boss portion 10d at the front end. The second boss portion 10d and the second through hole 10e are coaxial with the first boss portion 11c, the first recessed portion 11d, and the first through hole 11e.

[0029] The communication path 33 penetrates the end wall 10a in the front-rear direction. The communication path 33 communicates with the motor chamber 30. More specifically, the communication path 33 communicates with the rear side of the motor chamber 30.

[0030] The second plate 12 is positioned in front of the first plate 11. The second plate 12 has a second front surface 12a positioned in the front and a second rear surface 12b positioned in the rear. The second plate 12 is connected to the first plate 11 while bringing the second rear surface 12b into contact with the first front surface 11a.

[0031] A second recess 12c and a third through-hole 12d are formed in the second plate 12. The second recess 12c is recessed rearward from the second front surface 12a. The second recess 12c is formed to have a smaller diameter than the first recess 11d. The second recess 12c communicates with an impeller chamber 27a, which will be described later, at its front end. Also, a metal third seal ring 25 is provided inside the second recess 12c.

[0032] The third through-hole 12d is positioned at the center of the second plate 12 and penetrates the second plate 12 in the front-rear direction. As a result, the third through-hole 12d communicates with the second recess 12c at its front end and with the first recess 11d at its rear end. The second recess 12c and the third through-hole 12d are coaxial with the first boss portion 11c, the first recess 11d, and the first through-hole 11e.

[0033] A first shaft hole 35 is formed by these first boss portion 11c, first recess 11d, first through-hole 11e, second recess 12c, and third through-hole 12d. The first shaft hole 35 is positioned between the impeller chamber 27a and the motor chamber 30 in the housing 1 and communicates with the impeller chamber 27a and the motor chamber 30.

[0034] The third plate 13 is positioned behind the motor housing 10. The third plate 13 has a third front surface 13a positioned in the front and a third rear surface 13b positioned in the rear. The third plate 13 is connected to the motor housing 10 while bringing the third front surface 13a into contact with the second end surface 102 of the end wall 10a.

[0035] The third plate 13 is formed with a fourth through-hole 13c, a drain channel 13d, and a connection channel 13e. The fourth through-hole 13c is located at the center of the third plate 13 and penetrates the third plate 13 in the front-rear direction. The fourth through-hole 13c is coaxial with the second through-hole 10e.

[0036] As shown in FIG. 2, the fourth through-hole 13c is composed of a first hole portion 131 and a second hole portion 132. The first hole portion 131 constitutes the front portion of the fourth through-hole 13c. The first hole portion 131 is formed with the same diameter as the second through-hole 10e and communicates with the second through-hole 10e. The second hole portion 132 is located behind the first hole portion 131 and constitutes the rear portion of the fourth through-hole 13c. The second hole portion 132 is coaxial with the first hole portion 131 and is formed with a smaller diameter than the first hole portion 131. The second hole portion 132 communicates with a turbine chamber 29a described later. Thus, the fourth through-hole 13c is located between the second through-hole 10e and the turbine chamber 29a and communicates with the second through-hole 10e and the turbine chamber 29a.

[0037] The second boss portion 10d, the second through-hole 10e, and the fourth through-hole 13c form the second shaft hole 37. The second shaft hole 37 is located in the housing 1 between the motor chamber 30 and the turbine chamber 29a and communicates with the motor chamber 30 and the turbine chamber 29a.

[0038] The drain channel 13d extends in the radial direction of the housing 1 inside the third plate 13 while communicating with the first hole portion 131 and opens to the outer peripheral surface 130 of the third plate 13. Thereby, the drain channel 13d communicates the second shaft hole 37 with the outside of the housing 1.

[0039] The connection channel 13e extends forward inside the third plate 13 and communicates with the drain channel 13d at the rear end. Also, the front end of the connection channel 13e opens to the third front surface 13a of the third plate 13. The connection channel 13e communicates with the communication channel 33 when the third plate 13 is connected to the motor housing 10. Thereby, the communication channel 33 communicates with the drain channel 13d via the connection channel 13e.

[0040] As shown in FIG. 1, the compressor housing 14 is located in front of the second plate 12. The compressor housing 14 is cylindrical and is connected to the second plate 12 while being in contact with the second front surface 12a of the second plate 12. Thereby, the compressor housing 14 constitutes the front end portion of the housing 1.

[0041] The compressor housing 14 is formed with a first suction port 14a and a first discharge port 14b. The first suction port 14a is coaxial with the first shaft hole 35 and extends in the front-rear direction inside the compressor housing 14. The front end of the first suction port 14a opens to the front end surface 140 of the compressor housing 14. The first discharge port 14b extends radially inside the compressor housing 14 and opens to the outer peripheral surface 141 of the compressor housing 14.

[0042] Also, an impeller chamber 27a, a discharge chamber 27b, and a first diffuser flow path 27c are formed between the compressor housing 14 and the second front surface 12a. The impeller chamber 27a communicates with the first suction port 14a. The discharge chamber 27b extends around the impeller chamber 27a around the axis of the first suction port 14a. The discharge chamber 27b communicates with the first discharge port 14b. The first diffuser flow path 27c communicates the impeller chamber 27a and the discharge chamber 27b. Thereby, the impeller chamber 27a communicates with the first discharge port 14b through the first diffuser flow path 27c and the discharge chamber 27b.

[0043] The turbine housing 15 is located behind the third plate 13. The turbine housing 15 is cylindrical and is connected to the third plate 13 while being in contact with the third rear surface 13b of the third plate 13. Thereby, the turbine housing 15 constitutes the rear end portion of the housing 1.

[0044] The turbine housing 15 is formed with a second suction port 15a and a second discharge port 15b. The second suction port 15a extends radially inside the turbine housing 15 and opens to the outer peripheral surface 151 of the turbine housing 15. The second discharge port 15b is coaxial with the second shaft hole 37 and extends in the front-rear direction inside the turbine housing 15. The rear end of the second discharge port 15b opens to the rear end surface 150 of the turbine housing 15.

[0045] Also, between the turbine housing 15 and the third rear surface 13b, a turbine chamber 29a, a suction chamber 29b, and a second diffuser flow path 29c are formed. The turbine chamber 29a communicates with the second discharge port 15b. The suction chamber 29b extends around the turbine chamber 29a around the axis of the second discharge port 15b. The suction chamber 29b communicates with the second suction port 15a. The second diffuser flow path 29c communicates the turbine chamber 29a and the suction chamber 29b. Thereby, the turbine chamber 29a communicates with the second suction port 15a through the second diffuser flow path 29c and the suction chamber 29b.

[0046] In this way, in the housing 1, the impeller chamber 27a and the turbine chamber 29a are separated in the front-rear direction, and a motor chamber 30 is arranged between the impeller chamber 27a and the turbine chamber 29a.

[0047] A pipe 41 is connected to the first suction port 14a. Through the pipe 41, a cathode gas containing oxygen is inhaled from the outside of the housing 1 into the first suction port 14a. On the other hand, one end of a pipe 43 is connected to the first discharge port 14b. The other end of the pipe 43 is connected to the fuel cell 300. Thereby, the discharge chamber 27b and the fuel cell 300 are connected. Also, one end of a pipe 45 is connected to the pipe 43. The other end of the pipe 45 is connected to the supply path 31. Also, an intercooler 400 is provided in the pipe 45. Note that the intercooler 400 is a commercially available product.

[0048] Also, one end of a pipe 47 is connected to the fuel cell 300. And the other end of the pipe 47 is connected to the second suction port 15a. Thereby, the fuel cell 300 and the suction chamber 29b are connected. A pipe 49 is connected to the second discharge port 15b.

[0049] The electric motor 3 is housed in the motor chamber 30. The electric motor 3 has a stator 3a and a rotor 3b. The stator 3a is formed in a cylindrical shape extending in the front-rear direction and is fixed to the inner peripheral surface 104 of the peripheral wall 10b. The stator 3a is connected to a power supply device (not shown) provided outside the housing 1. The rotor 3b is formed in a cylindrical shape having a smaller diameter than the stator 3a and extending in the front-rear direction. The rotor 3b is disposed inside the stator 3a.

[0050] The drive shaft 5 is composed of a drive shaft main body 51 and a seal carrier 53. The drive shaft main body 51 is made of metal. The drive shaft main body 51 is formed in a columnar shape extending in the axial direction, that is, the front-rear direction, and has a first shaft portion 51a, a second shaft portion 51b, a third shaft portion 51c, and a fourth shaft portion 51d in order from the front to the rear. The first shaft portion 51a, the second shaft portion 51b, the third shaft portion 51c, and the fourth shaft portion 51d are coaxial with each other.

[0051] The first shaft portion 51a and the fourth shaft portion 51d are formed to have the same diameter. The first shaft portion 51a and the fourth shaft portion 51d have a diameter length of a first length L1 (see FIG. 2), and are formed to have the smallest diameter in the drive shaft main body 51. The second shaft portion 51b shown in FIG. 1 is formed to have a larger diameter than the first and fourth shaft portions 51a and 51d. The second shaft portion 51b is connected to the first shaft portion 51a at the front end. More specifically, the second shaft portion 51b has a diameter length of a second length L2 that is longer than the first length L1 (see FIG. 2). The third shaft portion 51c has a diameter length of a third length L3 that is longer than the second length L2. Thereby, the third shaft portion 51c is formed to have the largest diameter in the drive shaft main body 51. As shown in FIG. 1, the third shaft portion 51c is connected to the second shaft portion 51b at the front end and is connected to the fourth shaft portion 51d at the rear end.

[0052] As shown in FIG. 2, the seal carrier 53 is made of metal and is formed in a cylindrical shape. The seal carrier 53 is fixed to the fourth shaft portion 51d by being press-fitted into the fourth shaft portion 51d. At this time, the seal carrier 53 is in contact with the rear end of the third shaft portion 51c. In this way, the seal carrier 53 is integrated with the drive shaft main body 51.

[0053] The seal carrier 53 is composed of a first diameter portion 53a, a second diameter portion 53b, and a stepped portion 53c. These first diameter portion 53a, second diameter portion 53b, and stepped portion 53c are coaxial with each other. Further, the first diameter portion 53a, second diameter portion 53b, and stepped portion 53c are coaxial with the drive shaft main body 51 when the seal carrier 53 is fixed to the fourth shaft portion 51d.

[0054] The first diameter portion 53a constitutes the front portion of the seal carrier 53. The first diameter portion 53a has a diameter length of the third length L3 and has the same diameter as the third shaft portion 51c of the drive shaft main body 51. Thereby, the first diameter portion 53a and the third shaft portion 51c have the largest diameter in the drive shaft 5. Further, a first ring groove 55a is formed on the outer peripheral surface of the first diameter portion 53a.

[0055] The second diameter portion 53b constitutes the rear portion of the seal carrier 53. The second diameter portion 53b has a diameter length of the second length L2 and has a smaller diameter than the first diameter portion 53a. Further, the second diameter portion 53b has the same diameter as the second shaft portion 51b of the drive shaft main body 51. A second ring groove 55b is formed on the outer peripheral surface of the second diameter portion 53b.

[0056] Here, the third length L3 is shorter than the inner diameter length of the first hole portion 131 in the fourth through hole 13c and longer than the inner diameter length of the second hole portion 132. On the other hand, the second length L2 is shorter than the inner diameter length of the second hole portion 132. Thereby, the first diameter portion 53a including the third shaft portion 51c has a smaller diameter than the first hole portion 131 and a larger diameter than the second hole portion 132. And the second diameter portion 53b has a smaller diameter than the second hole portion 132.

[0057] The step portion 53c is located between the first diameter portion 53a and the second diameter portion 53b. The step portion 53c extends in the radial direction of the seal carrier 53 and is continuous with the first diameter portion 53a and the second diameter portion 53b.

[0058] As shown in FIG. 1, the drive shaft 5 is inserted into the first shaft hole 35 and the second shaft hole 37 within the housing 1. Further, in the drive shaft 5, the third shaft portion 51c of the drive shaft main body 51 is inserted into the rotor 3b within the motor chamber 30 and fixed to the rotor 3b. Furthermore, the third shaft portion 51c is inserted into the first radial bearing 21a within the first boss portion 11c and also inserted into the second radial bearing 21b within the second boss portion 10d. Thus, the drive shaft 5 is rotatable about the drive shaft center O. Note that the drive shaft center O extends parallel to the front-rear direction of the turbo-type fluid machine.

[0059] Also, in the drive shaft 5, the first shaft portion 51a of the drive shaft main body 51 extends into the impeller chamber 27a. Further, the second shaft portion 51b is inserted into the third seal ring 25 within the second recess 12c. Thereby, the third seal ring 25 is provided between the first shaft hole 35 and the drive shaft 5 and seals between the impeller chamber 27a and the motor chamber 30. Furthermore, the second shaft portion 51b is inserted into the first and second thrust bearings 23a, 23b within the first recess 11d and press-fitted into the support plate 57. The support plate 57 is located between the first thrust bearing 23a and the second thrust bearing 23b. Thereby, the support plate 57 sandwiches the first thrust bearing 23a in the front-rear direction between it and the second rear surface 12b, and sandwiches the second thrust bearing 23b in the front-rear direction between it and the wall surface of the first recess 11d.

[0060] Also, as shown in FIG. 1, in the drive shaft 5, the fourth shaft portion 51d of the drive shaft main body 51 extends into the turbine chamber 29a. Further, the rear end portion of the third shaft portion 51c and the seal carrier 53 enter into the fourth through-hole 13c. Specifically, the rear end portion of the third shaft portion 51c and the first diameter portion 53a of the seal carrier 53 enter into the first hole portion 131 of the fourth through-hole 13c, and the second diameter portion 53b of the seal carrier 53 enters into the second hole portion 132.

[0061] The impeller 7 is accommodated in the impeller chamber 27a. The impeller 7 is fixed to the first shaft portion 51a of the drive shaft main body 51. The turbine 9 is accommodated in the turbine chamber 29a. The turbine 9 is fixed to the fourth shaft portion 51d of the drive shaft main body 51. Thus, the drive shaft 5 connects the impeller 7, the turbine 9, and the electric motor 3. The impeller 7 rotates around the drive shaft center O in the impeller chamber 27a as the drive shaft 5 rotates around the drive shaft center O. Similarly, the turbine 9 rotates around the drive shaft center O in the turbine chamber 29a as the drive shaft 5 rotates around the drive shaft center O.

[0062] As shown in FIG. 2, both the first seal ring 61 and the second seal ring 63 are made of metal. The second seal ring 63 is formed with a smaller diameter than the first seal ring 61. The first seal ring 61 is provided on the first diameter portion 53a of the seal carrier 53 while being held in the first ring groove 55a. On the other hand, the second seal ring 63 is provided on the second diameter portion 53b of the seal carrier 53 while being held in the second ring groove 55b. Thereby, on the seal carrier 53, and thus on the drive shaft 5, the first seal ring 61 and the second seal ring 63 are arranged spaced apart in the front-rear direction. More specifically, the second seal ring 63 is located rearward of the first seal ring 61.

[0063] The first seal ring 61 and the second seal ring 63 enter the fourth through hole 13c together with the seal carrier 53 as the seal carrier 53 enters the fourth through hole 13c as described above. Then, the first seal ring 61 is disposed between the first hole portion 131 and the first diameter portion 53a. On the other hand, the second seal ring 63 is disposed between the second hole portion 132 and the second diameter portion 53b. Thus, the first seal ring 61 and the second seal ring 63 are provided between the second shaft hole 37 and the drive shaft 5 to seal between the motor chamber 30 and the turbine chamber 29a.

[0064] Also, in the second shaft hole 37, a first storage chamber S1 is formed by a seal carrier 53, the inner peripheral surface of the first hole portion 131, the inner peripheral surface of the second hole portion 132, a first seal ring 61, and a second seal ring 63. The first storage chamber S1 is an example of the "storage chamber" in the present invention. The first storage chamber S1 communicates with the drain passage 13d. Also, the first storage chamber S1 is sealed from the motor chamber 30 by the first seal ring 61, and is sealed from the turbine chamber 29a by the second seal ring 63.

[0065] The fuel cell 300 shown in FIG. 1 is a commercially available product and is composed of a plurality of fuel cells. The fuel cell 300 can generate electricity by causing a chemical reaction between a cathode gas and an anode gas.

[0066] In the turbo-type fluid machine configured as described above, when power is supplied from the power supply device to the electric motor 3, the electric motor 3 operates and the drive shaft 5 rotates around the drive shaft center O. For this reason, the impeller 7 rotates around the drive shaft center O in the impeller chamber 27a.

[0067] Thereby, the impeller 7 compresses the cathode gas sucked into the impeller chamber 27a from the first suction port 14a. The cathode gas compressed by the impeller 7 is discharged from the first discharge port 14b to the pipe 43. Then, the cathode gas discharged to the pipe 43 flows through the pipe 43 toward the fuel cell 300 and is supplied to the fuel cell 300. Thereby, power generation is performed in the fuel cell 300.

[0068] Also, a part of the cathode gas flowing through the pipe 43 flows through the pipe 45, and while being cooled by the intercooler 400, it is supplied into the motor chamber 30 from the supply passage 31. Thereby, the inside of the motor chamber 30 becomes a higher pressure than the inside of the first storage chamber S1 and the inside of the turbine chamber 29a.

[0069] On one hand, the exhaust from the fuel cell 300 containing the cathode gas that has completed power generation in the fuel cell 300 flows through the pipe 47, is introduced from the second suction port 15a into the suction chamber 29b, and further into the turbine chamber 29a. Thus, the exhaust from the fuel cell 300 drives the turbine 9 to rotate around the drive shaft center O in the turbine chamber 29a. Thereby, the turbine 9 assists when the electric motor 3 rotates the drive shaft 5 around the drive shaft center O. Here, the exhaust introduced into the turbine chamber 29a has a lower pressure compared to the cathode gas flowing through the pipe 43, that is, the cathode gas compressed by the impeller 7. Also, the exhaust introduced into the turbine chamber 29a is discharged from the second discharge port 15b into the pipe 49 by the turbine 9 rotating around the drive shaft center O, and is thus discharged to the outside of the housing 1.

[0070] By the way, the exhaust from the fuel cell 300 may contain the generated water produced during power generation in the fuel cell 300. Although this generated water can be discharged from the second discharge port 15b into the pipe 49 together with the exhaust, a part of the generated water may be stored in the turbine chamber 29a.

[0071] Here, in this turbo-type fluid machine, the first seal ring 61 and the second seal ring 63 are provided on the seal carrier 53, and the second seal ring 63 is separated on the rear side, that is, the turbine chamber 29a side, from the first seal ring 61.

[0072] Thus, in this turbo-type fluid machine, as shown by the dashed arrow in FIG. 2, even if the generated water in the turbine chamber 29a flows between the second hole portion 132 of the fourth through-hole 13c and the second seal ring 63, the generated water does not directly penetrate into the motor chamber 30, but is first stored in the first storage chamber S1. Then, in order for the generated water in the first storage chamber S1 to flow toward the motor chamber 30, it has to further flow between the first hole portion 131 of the fourth through-hole 13c and the second seal ring 63 while overcoming the stepped portion 53c. Therefore, it is difficult for the generated water in the first storage chamber S1 to penetrate into the motor chamber 30. Also, since a part of the cathode gas compressed by the impeller 7 is supplied into the motor chamber 30 from the supply passage 31, the pressure in the motor chamber 30 is higher than that in the first storage chamber S1 and the turbine chamber 29a. Also in this regard, it is difficult for the generated water in the first storage chamber S1 to penetrate into the motor chamber 30.

[0073] Then, the generated water in the first storage chamber S1 is discharged to the outside of the third plate 13 and thus to the outside of the housing 1 through the drain passage 13d. Thus, in this turbo-type fluid machine, the penetration of the generated water from the turbine chamber 29a into the motor chamber 30 through the second shaft hole 37 is preferably prevented.

[0074] Therefore, the turbo-type fluid machine of the first embodiment can preferably prevent a short circuit of the electric motor 3 caused by the generated water contained in the exhaust gas from the fuel cell 300.

[0075] In particular, in this turbo-type fluid machine, a communication path 33 is formed in the end wall 10a of the motor housing 10, and this communication path 33 communicates with the drain path 13d through a connection path 13e formed in the third plate 13. For this reason, even if, for example, the generated water in the first storage chamber S1 flows between the first hole portion 131 and the first seal ring 61 and enters the motor chamber 30 through the second through hole 10e and the second boss portion 10d, the generated water is discharged from the drain path 13d to the outside of the housing 1 through the communication path 33 and the connection path 13e before reaching the electric motor 3 due to the pressure difference between the inside of the motor chamber 30 and the outside of the housing 1 (see the dashed arrow in Fig. 2). Also in this regard, this turbo-type fluid machine suitably prevents a short circuit of the electric motor 3 caused by the generated water contained in the cathode gas.

[0076] (Example 2) As shown in Fig. 3, in the turbo-type fluid machine of Example 2, a second storage chamber S2 is formed by the seal carrier 53, the inner peripheral surface of the first hole portion 131, the inner peripheral surface of the second hole portion 132, the first seal ring 61, and the second seal ring 63. The second storage chamber S2 is also an example of the "storage chamber" in the present invention.

[0077] The second storage chamber S2 is composed of a storage chamber main body S21 and a groove portion S22. The storage chamber main body S21 is formed to have the same size as the first storage chamber S1 in the turbo-type fluid machine of Example 1, and is sealed from the motor chamber 30 by the first seal ring 61 and is sealed from the turbine chamber 29a by the second seal ring 63.

[0078] The groove portion S22 is formed in the first hole portion 131. The groove portion S22 is disposed at a position below the drive axis O in the first hole portion 131, and is recessed in a rectangular shape downward in the radial direction of the drive shaft 5 from the inner peripheral surface of the first hole portion 131. That is, the groove portion S22 is recessed in the direction in which gravity acts on the turbo-type fluid machine when the turbo-type fluid machine is mounted on a fuel cell vehicle. Thus, the groove portion S22 faces the storage chamber main body S21 and communicates with the storage chamber main body S21. Further, the groove portion S22 communicates with the drain passage 13d. Note that the groove portion S22 may be formed in an annular shape in the circumferential direction of the drive shaft 5 with respect to the inner peripheral surface of the first hole portion 131. Other configurations of this turbo-type fluid machine are the same as those of the turbo-type fluid machine of the first embodiment, and the same reference numerals are given to the same configurations, and detailed descriptions thereof are omitted.

[0079] In this turbo-type fluid machine, when the generated water in the turbine chamber 29a flows between the second hole portion 132 of the fourth through hole 13c and the second seal ring 63 and enters the second storage chamber S2, this generated water flows from the storage chamber main body S21 of the second storage chamber S2 to the groove portion S22 by the gravity acting on the housing 1 and is stored in the groove portion S22. Then, the generated water stored in the groove portion S22 is discharged to the outside of the housing 1 through the drain passage 13d.

[0080] As described above, since the second storage chamber S2 is composed of the storage chamber main body S21 and the groove portion S22, in this turbo-type fluid machine, it is possible to increase the amount of generated water stored in the second storage chamber S2. As a result, even when a large amount of generated water enters the second storage chamber S2 from the turbine chamber 29a, it is difficult for the generated water to overflow from the second storage chamber S2. Further, since the generated water is stored in the groove portion S22, it becomes more difficult for this generated water to flow between the first hole portion 131 and the first seal ring 61. For these reasons, in this turbo-type fluid machine, it is difficult for the generated water in the second storage chamber S2 to enter the motor chamber 30. Other operations of this turbo-type fluid machine are the same as those of the turbo-type fluid machine of the first embodiment.

[0081] In the above description, the present invention has been described with reference to Examples 1 and 2. However, the present invention is not limited to Examples 1 and 2 above, and it goes without saying that it can be appropriately modified and applied without departing from the gist thereof.

[0082] For example, in the turbo-type fluid machine of Examples 1 and 2, the drive shaft 5 is composed of a drive shaft main body 51 and a seal carrier 53. However, the present invention is not limited to this, and the drive shaft 5 may be composed of only the drive shaft main body 51, and the first seal ring 61 and the second seal ring 63 may be provided for the third shaft portion 51c and the fourth shaft portion 51d, respectively.

[0083] Also, in the turbo-type fluid machine of Examples 1 and 2, the second seal ring 63 is formed with a smaller diameter than the first seal ring 61. However, the present invention is not limited to this, and the first seal ring 61 and the second seal ring 63 may be formed with the same diameter.

[0084] Further, when sealing between the motor chamber 30 and the turbine chamber 29a, in addition to the first seal ring 61 and the second seal ring 63, other sealing members such as seal rings may be used.

[0085] Also, the formation of the supply passage 31, the communication passage 33, and the connection passage 13e may be omitted.

[0086] Also, in the turbo-type fluid machine of Examples 1 and 2, the drain passage 13d opens to the outer peripheral surface 130 of the third plate 13. However, the present invention is not limited to this, and the drain passage 13d may communicate with the outside of the housing 1 by opening to the second discharge port 15b. In this case, the generated water flowing through the drain passage 13d is discharged from the second discharge port 15b to the outside of the housing 1.

Industrial Applicability

[0087] The present invention can be used in a fuel cell vehicle, a fuel cell system, or the like.

Explanation of Reference Numerals

[0088] 1... Housing 3... Electric motor 5…Drive shaft 7…Impeller 9…Turbine 13d…Drainage channel 27a…Impeller chamber 29a…Turbine chamber 30…Motor chamber 31…Supply path 33…Communication path 35…First shaft hole 37…Second shaft hole 53a…First diameter part 53b…Second diameter part 53c…Step part 61…First seal ring (first sealing member, sealing member) 63…Second seal ring (first sealing member, sealing member) 300…Fuel cell S1…First storage chamber (storage chamber) S2…Second storage chamber (storage chamber) S22…Groove part

Claims

1. A housing having an impeller chamber, a turbine chamber, a motor chamber located between the impeller chamber and the turbine chamber, a first shaft hole located between the impeller chamber and the motor chamber and communicating with the impeller chamber and the motor chamber, and a second shaft hole located between the motor chamber and the turbine chamber and communicating with the motor chamber and the turbine chamber, an electric motor housed in the motor chamber, an impeller housed in the impeller chamber and compressing cathode gas supplied to a fuel cell by the rotation of the electric motor, a turbine housed in the turbine chamber and rotated by the exhaust gas from the fuel cell, a drive shaft inserted through the first shaft hole and the second shaft hole and connecting the electric motor, the impeller, and the turbine, a turbo-type fluid machine comprising a sealing member provided between the second shaft hole and the drive shaft and sealing between the motor chamber and the turbine chamber, wherein the sealing member has a first sealing member and a second sealing member spaced apart from the first sealing member toward the turbine chamber side in the axial direction of the drive shaft, a storage chamber capable of storing the generated water contained in the exhaust gas is formed by the drive shaft, the second shaft hole, the first sealing member, and the second sealing member, and a drain passage communicating with the storage chamber and discharging the generated water in the storage chamber to the outside of the housing is formed in the housing. The turbo-type fluid machine is characterized by this.

2. The drive shaft has a first diameter portion, a second diameter portion coaxially aligned with the first diameter portion and formed with a smaller diameter than the first diameter portion and located on the turbine chamber side in the axial direction with respect to the first diameter portion, and a stepped portion coaxially aligned with the first diameter portion and the second diameter portion and located between the first diameter portion and the second diameter portion, wherein the first sealing member is provided on the first diameter portion, and the second sealing member is formed with a smaller diameter than the first sealing member and provided on the second diameter portion. The turbo-type fluid machine according to Claim 1.

3. The storage chamber is formed in the second shaft hole and has a groove portion recessed in the direction in which gravity acts. The turbo-type fluid machine according to Claim 1 or 2.

4. A supply passage for supplying a part of the cathode gas compressed by the impeller into the motor chamber and a communication passage connecting the motor chamber and the drain passage are formed in the housing. The turbo-type fluid machine according to any one of Claims 1 to 3.

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