Turbo-type fluid machinery

Abstract

The present invention provides a turbo fluid machine. The thrust foil bearing (30) includes: a wave foil (32) formed of an elastic thin plate having a corrugated shape; and a top foil (33) formed of an elastic thin plate having a bearing surface (33c) facing the bearing surface (241d) of the thrust ring (the third support portion 24d) and elastically supported by the wave foil (32). The wave foil (32) is divided in the radial direction, and the ridge line (321e) of the peak portion of the outer peripheral side foil (321) extends obliquely in such a manner that it advances in the other direction around the axis as it advances from the inner peripheral edge (321a) of the outer peripheral side foil (321) toward the outer peripheral side. The ridge line (322e) of the peak portion of the inner peripheral side foil (322) extends obliquely in such a manner that it advances in the other direction around the axis as it advances from the outer peripheral edge (322a) of the inner peripheral side foil (322) toward the inner peripheral side.

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. The turbo-type fluid machine includes: a rotating shaft; a working body that rotates integrally with the rotating shaft to pump an external fluid; a housing that houses the rotating shaft and the working body; and a thrust foil bearing that supports the rotating shaft so as to be rotatable relative to the housing in the axial direction of the rotating shaft.

[0003] On the rotating shaft, a plate-like thrust ring is integrally provided so as to extend from the circumferential surface toward the radial direction. The thrust ring is configured to be rotatable integrally with the rotating shaft. The thrust foil bearing includes a bearing housing, a plurality of wave foils, and a plurality of top foils.

[0004] The bearing housing has an insertion hole through which the rotating shaft is inserted, and faces the thrust ring in the axial direction of the rotating shaft. The plurality of wave foils are arranged and mounted around the insertion hole on the end face of the bearing housing on the thrust ring side. Each wave foil is formed of an elastic thin plate having a corrugated shape. Each top foil is formed of an elastic thin plate having a bearing surface facing the thrust ring, and its back surface is elastically supported by each wave foil. The end face of the thrust ring on the top foil side serves as a bearing surface facing the bearing surface of the top foil in the axial direction.

[0005] In the thrust foil bearing, the top foil supports the relatively rotating thrust ring in a contact state during low-speed rotation of the rotating shaft. When the rotating shaft rotates at high speed, the thrust ring is supported in a non-contact state by a fluid film generated in the bearing gap between the bearing surface and the bearing surface.

[0006]

Prior Art Documents

[0007]

Patent Documents

[0008] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2020-115021 Summary of the Invention

[0009]

Problems to be Solved by the Invention

[0010] However, in the thrust foil bearing of the turbo-type fluid machine as described above, there is the following problem: The fluid compressed in the bearing gap leaks from the sides of the inner peripheral side and the outer peripheral side of the bearing gap due to the pressure difference with the surroundings, and the load capacity of the bearing decreases due to the decrease in the fluid film pressure.

[0011] In view of such problems, for example, a countermeasure is considered in which a so-called herringbone groove with a V shape whose top faces the front side in the rotation direction of the rotating shaft is provided on the bearing surface of the top foil and the surface to be borne of the thrust ring. According to this countermeasure, the fluid guided by the herringbone groove in the bearing clearance is directed toward the top of the V shape, that is, introduced (pulled in) from the outer peripheral side and the inner peripheral side in the top foil toward the radial center, so that leakage of the fluid from the side of the bearing clearance can be suppressed.

[0012] However, in the above countermeasure, correspondingly to the provision of the herringbone groove, the contact area between the bearing surface and the surface to be borne during low-speed rotation of the rotating shaft decreases and the contact surface pressure increases. Therefore, there is a problem that the durability of the top foil is reduced due to wear, sintering, etc.

[0013] The present invention has been completed in view of the above-mentioned conventional situation, and the problem to be solved is to provide a turbo-type fluid machine that can suppress a decrease in the fluid film pressure in the thrust foil bearing and thus suppress a decrease in the load capacity of the thrust foil bearing without reducing the durability of the top foil.

[0014]

Technical means for solving the problem

[0015] The turbo-type fluid machine of the present invention includes:

[0016] A rotating shaft that rotates in one direction around the axis;

[0017] A plate-shaped thrust ring provided on the rotating shaft so as to extend from the circumferential surface toward the radial direction and capable of rotating integrally with the rotating shaft;

[0018] A working body that rotates integrally with the rotating shaft to compress external fluid;

[0019] A housing that houses the rotating shaft and the working body; and

[0020] A thrust foil bearing that supports the rotating shaft so as to be rotatable relative to the housing in the axial direction of the rotating shaft,

[0021] characterized in that

[0022] The thrust foil bearing includes: a bearing housing having an insertion hole through which the rotating shaft is inserted and facing the thrust ring in the axial direction; a plurality of wave foils arranged and mounted around the insertion hole on the end face of the bearing housing on the thrust ring side; and a plurality of top foils formed of elastic thin plates having a bearing surface facing the thrust ring on one side and elastically supported by each of the wave foils on the other side,

[0023] The wave foil is formed of an elastic thin plate having a corrugated plate shape in which the ridges of the mountain portions protruding toward the thrust ring side are arranged in the circumferential direction of the rotating shaft,

[0024] Each of the wave foils is divided in the radial direction of the rotating shaft into an outer peripheral side foil disposed on the outer peripheral side and an inner peripheral side foil disposed on the inner peripheral side.

[0025] The ridge line in each of the outer peripheral side foils extends obliquely in such a manner that as it proceeds from the inner peripheral side edge of the outer peripheral side foil toward the outer peripheral side, it proceeds in the other direction around the axis.

[0026] The ridge line in each of the inner peripheral side foils extends obliquely in such a manner that as it proceeds from the outer peripheral side edge of the inner peripheral side foil toward the inner peripheral side, it proceeds in the other direction around the axis.

[0027] In a thrust foil bearing, when the thrust ring rotates together with the rotating shaft in one direction around the axis, at low speed rotation, the top foil supports the relatively rotating thrust ring in a contacting state. At this time, the end face on the top foil side of the thrust ring, that is, the face facing the bearing surface of the top foil in the axial direction of the rotating shaft, becomes the bearing surface. If the rotating shaft rotates at high speed, the fluid film pressure in the bearing clearance between the bearing surface of the top foil and the bearing surface of the thrust ring increases. As a result, the top foil elastically supported by the wave foil elastically deforms while accompanying the elastic deformation of the wave foil and floats up from the thrust ring, and supports the thrust ring in a non-contact state via the fluid film generated in the bearing clearance. At this time, in the top foil, the portion supported by the peak portion of the wave foil elastically deforms. As a result, the wave plate shape of the wave foil is transferred to the top foil, and the top foil also becomes a wave plate shape in which the ridge lines of the peaks protruding toward the thrust ring side are arranged in the circumferential direction.

[0028] In the thrust foil bearing of the turbine type fluid machine of the present invention, the wave foil is divided in the radial direction of the rotating shaft and has an outer peripheral side foil disposed on the outer peripheral side and an inner peripheral side foil disposed on the inner peripheral side. Further, the ridge line in the outer peripheral side foil extends obliquely in such a manner that as it proceeds from the inner peripheral side edge of the outer peripheral side foil toward the outer peripheral side, it proceeds in the other direction around the axis, and the ridge line in the inner peripheral side foil extends obliquely in such a manner that as it proceeds from the outer peripheral side edge of the inner peripheral side foil toward the inner peripheral side, it proceeds in the other direction around the axis. That is, the ridge line of the peak portion in the outer peripheral side foil extends obliquely in such a manner that as it proceeds from the inner peripheral side toward the outer peripheral side, it proceeds to the rear side in the rotation direction of the rotating shaft, and the ridge line of the peak portion in the inner peripheral side foil extends obliquely in such a manner that as it proceeds from the outer peripheral side toward the inner peripheral side, it proceeds to the rear side in the rotation direction of the rotating shaft.

[0029] In such a configuration, the ridge line of the wave plate shape of the wave foil is transferred and formed on the peak portion of the top foil, becoming a so-called herringbone shape with the V-shaped top facing the front side in the rotation direction, which is one direction around the axis. In this way, in the bearing clearance between the bearing surface of the top foil and the surface to be borne of the thrust ring, the fluid guided by the herringbone-shaped ridge line is introduced toward the V-shaped top of the herringbone shape, that is, from the outer peripheral side and the inner peripheral side in the top foil toward the radial center. Therefore, it is possible to suppress the lateral leakage of the fluid compressed in the bearing clearance from the outer peripheral side and the inner peripheral side of the bearing clearance, and it is possible to suppress the reduction of the fluid film pressure in the bearing clearance.

[0030] On the other hand, since no grooves are formed on both the bearing surface and the surface to be borne, the contact area between the bearing surface and the surface to be borne during the low-speed rotation of the rotating shaft where both slide does not decrease correspondingly due to the formation of grooves. Therefore, the durability of the top foil will not be reduced due to wear, sintering, etc.

[0031] Therefore, according to the turbo-type fluid machine of the present invention, it is possible to suppress the reduction of the fluid film pressure in the thrust foil bearing and thus suppress the reduction of the load capacity of the thrust foil bearing without reducing the durability of the top foil.

[0032] The housing may have a cooling passage through which a cooling fluid for cooling the thrust foil bearing flows. Preferably, the cooling passage is formed such that the cooling fluid flows from the inner peripheral side of the top foil toward the outer peripheral side or from the outer peripheral side toward the inner peripheral side between the bearing housing and each top foil.

[0033] In the thrust foil bearing, during low-speed rotation, the top foil supports the relatively rotating thrust ring in a contact state, so heat is generated due to the sliding between the two. In addition, during high-speed rotation, heat is also generated due to the shearing of the fluid film between the thrust ring and the top foil. The top foil is composed of an elastic thin plate with a small heat capacity. Therefore, the top foil easily becomes hot, and the heat resistance of the top foil easily becomes a problem. In this regard, according to the above configuration, since the cooling fluid flows between the bearing housing and the top foil, the top foil can be cooled by the cooling fluid, and the problem of the heat resistance of the top foil can be suppressed.

[0034] On the other hand, in the case where the cooling passage is formed such that the cooling fluid flows between the bearing housing and the top foil, the fluid leaking from the side of the bearing clearance flows out to the outside together with the cooling fluid through the cooling passage. Therefore, the leakage of the fluid from the side of the bearing clearance is directly related to the reduction of the fluid film pressure. Therefore, suppressing the leakage from the side of the bearing clearance becomes more important. In this regard, in the turbo-type fluid machine of the present invention, since the leakage of the fluid in the bearing clearance from the side can be suppressed by using the ridge line transferred to the peak portion of the top foil, the effect becomes remarkable in the case where the above-described cooling passage is formed.

[0035] Preferably, the relationship between the radial width Wout of the outer peripheral side foil and the radial width Win of the inner peripheral side foil satisfies Wout > Win.

[0036] In the thrust foil bearing, due to the action of centrifugal force, the leakage of fluid from the side of the bearing clearance is larger on the outer peripheral side than on the inner peripheral side. In this case, since the radial width Wout of the outer peripheral side foil is larger than the radial width Win of the inner peripheral side foil, the force for introducing the fluid that tends to leak laterally to the outer peripheral side toward the center in the radial direction becomes larger, and the leakage of the fluid to the outer peripheral side can be effectively suppressed.

[0037] Preferably, the relationship between the acute angle θout formed by the ridge line in the outer peripheral side foil with respect to the radial direction and the acute angle θin formed by the ridge line in the inner peripheral side foil with respect to the radial direction satisfies θout > θin.

[0038] In this case, since the acute angle θout formed by the ridge line in the outer peripheral side foil with respect to the radial direction is larger than the acute angle θin formed by the ridge line in the inner peripheral side foil with respect to the radial direction, the force for introducing the fluid that tends to leak laterally to the outer peripheral side toward the center in the radial direction becomes larger, and the leakage of the fluid to the outer peripheral side can be effectively suppressed.

[0039] Preferably, the outer peripheral side foil is divided in the radial direction into a first outer peripheral side foil disposed on the outer peripheral side and a second outer peripheral side foil disposed on the inner peripheral side. And preferably, the relationship between the acute angle θout1 formed by the ridge line in the first outer peripheral side foil with respect to the radial direction and the acute angle θout2 formed by the ridge line in the second outer peripheral side foil with respect to the radial direction satisfies θout1 > θout2.

[0040] According to the above configuration, the force for introducing the fluid that tends to leak laterally to the outer peripheral side toward the center in the radial direction becomes larger, and the leakage of the fluid to the outer peripheral side can be more effectively suppressed.

[0041]

Advantages of the Invention

[0042] According to the turbomachine of the present invention, it is possible to suppress a decrease in the fluid film pressure in the thrust foil bearing and thus suppress a decrease in the load capacity of the thrust foil bearing without reducing the durability of the top foil. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 is a cross-sectional view of a turbo compressor according to an embodiment.

[0044] Figure 2 is an enlarged cross-sectional view showing a part of the turbo compressor according to the embodiment.

[0045] Figure 3 is an enlarged cross-sectional view showing a part of the turbo compressor according to the embodiment.

[0046] Figure 4 It is a top view showing the shape and configuration of the wave foil for a turbine compressor according to an embodiment.

[0047] Figure 5 It is a top view showing the shape and configuration of the top foil for a turbine compressor according to an embodiment.

[0048] Figure 6 It is a top view showing the shape of the wave foil for a turbine compressor according to an embodiment.

[0049] Figure 7 It is a cross-sectional view showing the operation of the thrust foil bearing for a turbine compressor according to an embodiment.

[0050] Figure 8 It is a cross-sectional view showing the operation of the thrust foil bearing for a turbine compressor according to an embodiment.

[0051] Figure 9 It is a top view showing Modification Example 1 of the wave foil for a turbine compressor according to an embodiment.

[0052] Figure 10 It is a top view showing Modification Example 2 of the wave foil for a turbine compressor according to an embodiment.

[0053] Figure 11 It is a top view showing Modification Example 3 of the wave foil for a turbine compressor according to an embodiment. Detailed Description of the Embodiment

[0054] Hereinafter, embodiments embodying the present invention will be described with reference to the accompanying drawings.

[0055] (Embodiment)

[0056] In this embodiment, the turbine fluid machine of the present invention is embodied as a turbine compressor 10. The turbine compressor 10 is mounted on a fuel cell vehicle equipped with a fuel cell system 1. The fuel cell system 1 supplies oxygen and hydrogen to the in-vehicle fuel cell to generate electricity. The turbine compressor 10 compresses the air containing oxygen supplied to the in-vehicle fuel cell.

[0057] As Figure 1 shown, the turbine compressor 10 as a turbine fluid machine includes a housing 11. The housing 11 is made of a metal material, for example, aluminum alloy. The housing 11 has a motor housing 12, a compressor housing 13, a turbine housing 14, a first plate 15, a second plate 16, and a third plate 17.

[0058] The motor housing 12 has a plate-shaped end wall 12a and a peripheral wall 12b. The peripheral wall 12b extends in a cylindrical shape from the outer peripheral portion of the end wall 12a. The first plate 15 is connected to the end portion on the opening side of the peripheral wall 12b of the motor housing 12 to close the opening of the peripheral wall 12b.

[0059] The motor chamber S1 is defined by the inner surface 121a of the end wall 12a of the motor housing 12, the inner peripheral surface 121b of the peripheral wall 12b, and the end face 15a on the motor housing 12 side of the first plate 15. An electric motor 18 is housed in the motor chamber S1.

[0060] The first plate 15 has a first bearing holding portion 20. The first bearing holding portion 20 projects from the central portion of the end face 15a of the first plate 15 toward the electric motor 18. The first bearing holding portion 20 is cylindrical.

[0061] On the end face 15b of the first plate 15 opposite to the motor housing 12, a recess 15c having a bottom face 15d is formed. The recess 15c is in the shape of a circular hole. The inside of the cylinder of the first bearing holding portion 20 penetrates through the first plate 15 and opens at the bottom face 15d of the recess 15c. The axis of the recess 15c coincides with the axis of the first bearing holding portion 20. The inner peripheral surface 15e of the recess 15c connects the end face 15b and the bottom face 15d.

[0062] The motor housing 12 has a second bearing holding portion 22. The second bearing holding portion 22 projects from the central portion of the inner surface 121a of the end wall 12a of the motor housing 12 toward the electric motor 18. The second bearing holding portion 22 is cylindrical. The inside of the cylinder of the second bearing holding portion 22 penetrates through the end wall 12a of the motor housing 12 and opens at the outer surface 122a of the end wall 12a. The axis of the first bearing holding portion 20 coincides with the axis of the second bearing holding portion 22.

[0063] As Figure 2 shown, the second plate 16 is connected to the end face 15b of the first plate 15. An axial insertion through-hole 16a is formed in the central portion of the second plate 16. The axial insertion through-hole 16a communicates with the inside of the recess 15c. The axis of the axial insertion through-hole 16a coincides with the axis of the recess 15c and the axis of the first bearing holding portion 20. The thrust bearing housing chamber S2 is defined by the end face 16b on the first plate 15 side of the second plate 16 and the recess 15c of the first plate 15.

[0064] The compressor housing 13 is cylindrical with a circular hole-shaped air suction port 13a for sucking air. The compressor housing 13 is connected to the end face 16c of the second plate 16 opposite to the first plate 15. The axis of the air suction port 13a of the compressor housing 13, the axis of the axial insertion through-hole 16a of the second plate 16, and the axis of the first bearing holding portion 20 coincide. The air suction port 13a opens at the end face of the compressor housing 13 opposite to the second plate 16.

[0065] Between the end face 16c of the compressor housing 13 and the second plate 16, a first impeller chamber 13b, a discharge (exhaust) chamber 13c, and a first diffuser flow path 13d are formed. The first impeller chamber 13b communicates with the suction port 13a. The discharge chamber 13c extends around the axis of the suction port 13a surrounding the first impeller chamber 13b. The first diffuser flow path 13d connects the first impeller chamber 13b and the discharge chamber 13c. The first impeller chamber 13b communicates with the shaft insertion through-hole 16a of the second plate 16.

[0066] As Figure 3 As shown, the third plate 17 is connected to the outer surface 122a of the end wall 12a of the motor housing 12. A shaft insertion through-hole 17a is formed in the central portion of the third plate 17. The shaft insertion through-hole 17a communicates with the inside of the cylinder of the second bearing holder 22. The axis of the shaft insertion through-hole 17a coincides with the axis of the second bearing holder 22.

[0067] The turbine housing 14 is cylindrical with a circular discharge hole 14a for discharging air. The turbine housing 14 is connected to the end face 17b of the third plate 17 on the side opposite to the motor housing 12. The axis of the discharge hole 14a of the turbine housing 14, the axis of the shaft insertion through-hole 17a of the third plate 17, and the axis of the second bearing holder 22 coincide. The discharge hole 14a opens at the end face of the turbine housing 14 on the side opposite to the third plate 17.

[0068] Between the end face 17b of the turbine housing 14 and the third plate 17, a second impeller chamber 14b, a suction chamber 14c, and a second diffuser flow path 14d are formed. The second impeller chamber 14b communicates with the discharge hole 14a. The suction chamber 14c extends around the axis of the discharge hole 14a surrounding the second impeller chamber 14b. The second diffuser flow path 14d connects the second impeller chamber 14b and the suction chamber 14c. The second impeller chamber 14b communicates with the shaft insertion through-hole 17a of the third plate 17.

[0069] As Figure 1 As shown, a rotating body 24 is housed in the housing 11. The rotating body 24 has a rotating shaft 24a as a shaft portion, a first support portion 24b, a second support portion 24c, and a third support portion 24d. The rotating shaft 24a has a first end portion 24e as an end portion on the compressor housing 13 side and a second end portion 24f as an end portion on the turbine housing 14 side. The first support portion 24b is provided at a portion of the outer peripheral surface 240a of the rotating shaft 24a near the first end portion 24e and is disposed inside the cylinder of the first bearing holder 20. The first support portion 24b is integrally formed with the rotating shaft 24a and protrudes annularly from the outer peripheral surface 240a of the rotating shaft 24a.

[0070] The second support portion 24c is provided at a position on the outer peripheral surface 240a of the rotary shaft 24a near the second end portion 24f and is disposed inside the cylinder of the second bearing holder 22. The second support portion 24c has a cylindrical shape and is fixed to the outer peripheral surface 240a of the rotary shaft 24a in a state of protruding annularly from the outer peripheral surface 240a of the rotary shaft 24a. The second support portion 24c can rotate integrally with the rotary shaft 24a.

[0071] The third support portion 24d is disposed in the thrust bearing housing chamber S2. The third support portion 24d has a disc shape and is fixed to the outer peripheral surface 240a of the rotary shaft 24a in a state of extending radially from the outer peripheral surface 240a of the rotary shaft 24a and protruding annularly. The third support portion 24d can rotate integrally with the rotary shaft 24a. The third support portion 24d is disposed at a position separated from the electric motor 18 in the axial direction of the rotary shaft 24a. The third support portion 24d corresponds to the thrust ring in the present invention.

[0072] In the following description, the axial direction, the circumferential direction, and the radial direction respectively mean the axial direction, the circumferential direction, and the radial direction of the rotary shaft 24a. One side of the circumferential direction coincides with one direction around the axis of the rotary shaft 24a, and the other side of the circumferential direction coincides with the other direction around the axis of the rotary shaft 24a. In addition, the first end portion 24e side of the rotary shaft 24a is set as one side of the axial direction, and the second end portion 24f side of the rotary shaft 24a is set as the other side of the axial direction.

[0073] At the first end portion 24e of the rotary shaft 24a, a first impeller 25 as a working body is connected. The first impeller 25 is disposed at a position on the rotary shaft 24a closer to the first end portion 24e than the third support portion 24d. The first impeller 25 is housed in the first impeller chamber 13b. At the second end portion 24f of the rotary shaft 24a, a second impeller 26 is connected. The second impeller 26 is disposed at a position on the rotary shaft 24a closer to the second end portion 24f than the second support portion 24c. The second impeller 26 is housed in the second impeller chamber 14b. The housing 11 houses the first impeller 25, the second impeller 26, and the rotating body 24.

[0074] A first sealing member 27 is provided between the shaft insertion through hole 16a of the second plate 16 and the rotating body 24. The first sealing member 27 suppresses the leakage of air from the first impeller chamber 13b toward the motor chamber S1. A second sealing member 28 is provided between the shaft insertion through hole 17a of the third plate 17 and the rotating body 24. The second sealing member 28 suppresses the leakage of air from the second impeller chamber 14b toward the motor chamber S1. The first sealing member 27 and the second sealing member 28 are, for example, sealing rings.

[0075] The electric motor 18 includes a cylindrical rotor 36 and a cylindrical stator 35. The rotor 36 is fixed to the rotating shaft 24a. The stator 35 is fixed to the housing 11. The rotor 36 is disposed radially inside the stator 35 and rotates integrally with the rotating body 24. The rotor 36 has a cylindrical rotor core 36a attached and fixed to the rotating shaft 24a and a plurality of permanent magnets (not shown) provided on the rotor core 36a. The stator 35 surrounds the rotor 36. The stator 35 has a cylindrical stator core 35a fixed to the inner peripheral surface 121b of the peripheral wall 12b of the motor housing 12 and a coil 34 wound around the stator core 35a. The rotating body 24 rotates integrally with the rotor 36 when current flows from a battery (not shown) to the coil 34.

[0076] The fuel cell system 1 includes a fuel cell stack 100 as a vehicle-mounted fuel cell, a turbo compressor 10, a supply flow path L1, a discharge flow path L2, and a branch flow path L3. The fuel cell stack 100 is composed of a plurality of fuel cells. The supply flow path L1 connects the discharge chamber 13c and the fuel cell stack 100. The discharge flow path L2 connects the fuel cell stack 100 and the suction chamber 14c. A charge air cooler 110 is provided in the middle of the branch flow path L3 branched from the supply flow path L1. The charge air cooler 110 cools the air flowing in the branch flow path L3.

[0077] When the rotating body 24 rotates integrally with the rotor 36, the first impeller 25 and the second impeller 26 rotate integrally with the rotating body 24. Then, the air sucked from the suction port 13a is compressed by the first impeller 25 in the first impeller chamber 13b and discharged from the discharge chamber 13c through the first diffuser flow path 13d. The air discharged from the discharge chamber 13c is supplied to the fuel cell stack 100 via the supply flow path L1. The air supplied to the fuel cell stack 100 is discharged as the exhaust gas of the fuel cell stack 100 to the discharge flow path L2 after being used for generating power by the fuel cell stack 100. The exhaust gas of the fuel cell stack 100 is sucked into the suction chamber 14c via the discharge flow path L2. The exhaust gas of the fuel cell stack 100 sucked into the suction chamber 14c is discharged to the second impeller chamber 14b through the second diffuser flow path 14d. The second impeller 26 rotates by the exhaust gas of the fuel cell stack 100 discharged to the second impeller chamber 14b. The rotating body 24 rotates by using the rotation of the second impeller 26 rotated by the exhaust gas of the fuel cell stack 100 in addition to the rotation based on the drive of the electric motor 18. Therefore, the first impeller 25 as the working body rotates integrally with the rotating body 24 and compresses the air as the external fluid. The exhaust gas of the fuel cell stack 100 discharged to the second impeller chamber 14b is discharged to the outside from the discharge port 14a.

[0078] The turbo compressor 10 has a pair of thrust foil bearings 30, 30 and a pair of radial foil bearings 40, 40. The pair of thrust foil bearings 30, 30 support the rotating shaft 24a so as to be rotatable relative to the housing 11 in the axial direction of the rotating shaft 24a. The pair of radial foil bearings 40, 40 support the rotating shaft 24a so as to be rotatable relative to the housing 11 in a direction orthogonal to the axial direction of the rotating shaft 24a.

[0079] The pair of thrust foil bearings 30, 30 are disposed in the thrust bearing housing chamber S2. The pair of thrust foil bearings 30, 30 are arranged to sandwich the third support portion 24d serving as a thrust ring. The pair of thrust foil bearings 30, 30 are opposite to each other in the axial direction of the rotating shaft 24a with respect to the third support portion 24d. One of the thrust foil bearings 30 is disposed on the side of the first end portion 24e of the rotating shaft 24a with respect to the third support portion 24d. The other thrust foil bearing 30 is disposed on the side of the second end portion 24f of the rotating shaft 24a with respect to the third support portion 24d.

[0080] The end face on the side of the first end portion 24e of the rotating shaft 24a in the third support portion 24d is provided as a bearing surface 241d supported in the axial direction by one of the thrust foil bearings 30 (refer to Figure 2 , Figure 7 ). Similarly, the end face on the side of the second end portion 24f of the rotating shaft 24a in the third support portion 24d is provided as a bearing surface 241d supported in the axial direction by the other thrust foil bearing 30.

[0081] Since the pair of thrust foil bearings 30, 30 have substantially the same configuration, only the configuration of one of the thrust foil bearings 30 will be described, and the description of the configuration of the other thrust foil bearing 30 will be omitted.

[0082] In the following description, it is assumed that when the rotating body 24 rotates integrally with the rotor 36, the rotating shaft 24a rotates in one direction around the axis. The one direction around the axis here is the counterclockwise direction as indicated by the arrow R showing the rotation direction of the rotating shaft 24a in Figures 4 to 8 , Figure 4 .

[0083] As shown in Figure 4 and Figure 5 , the thrust foil bearing 30 includes a bearing housing 31, six wave foils 32 mounted on the bearing housing 31, and six top foils 33 mounted on the bearing housing 31 at positions corresponding to the respective wave foils 32. The outer shapes of the wave foils 32 and the top foils 33 are substantially fan-shaped in plan view. The wave foils 32 and the top foils 33 are formed by shaping an elastic thin plate made of a metal such as stainless steel into a predetermined shape.

[0084] The bearing housing 31 is constituted by a part of the second plate 16. That is, the bearing housing 31 is constituted by the second plate 16 in the part of the end face 16b of the second plate 16 that demarcates the thrust bearing housing chamber S2. The bearing housing 31 faces the third support portion 24d in the axial direction of the rotary shaft 24a. An insertion hole 31a through which the rotary shaft 24a is inserted is formed in the bearing housing 31. In addition, the bearing housing 31 of the other thrust foil bearing 30 is constituted by the first plate 15 in the part of the concave portion 15c that demarcates the thrust bearing housing chamber S2.

[0085] Six wave foils 32 are arranged at equal intervals in the circumferential direction of the rotary shaft 24a on the end face of the bearing housing 31 on the side of the third support portion 24d, and are arranged and mounted around the insertion hole 31a.

[0086] One end of each wave foil 32 in the circumferential direction is fixed to the bearing housing 31 by welding. That is, one end of the wave foil 32 in the circumferential direction is set as the fixed end 32a, and the other end in the circumferential direction is set as the free end 32b. In addition, for the wave foil 32, the other end in the circumferential direction may be set as the fixed end, and one end in the circumferential direction may be set as the free end.

[0087] As Figure 7 shown, the wave foil 32 is set in a corrugated plate shape in which the mountain portions 32c and the valley portions 32d are alternately arranged in the circumferential direction of the rotary shaft 24a. That is, the ridge lines 32e of the mountain portions 32c are arranged in the circumferential direction of the rotary shaft 24a. Each mountain portion 32c projects toward the third support portion 24d side and can be in contact with the top foil 33 to elastically support the top foil 33. In the top foil 33, the surface opposite to the surface elastically supported by the wave foil 32 is set as the bearing surface 33c that faces the bearing surface 241d of the third support portion 24d in the axial direction.

[0088] Each wave foil 32 is divided in the radial direction of the rotary shaft 24a. The outer peripheral side foil 321 arranged on the outer peripheral side and the inner peripheral side foil 322 arranged on the inner peripheral side are integrally connected by a connecting portion 32f at one end in the circumferential direction. Connecting the outer peripheral side foil 321 and the inner peripheral side foil 322 by the connecting portion 32f is for easy handling and assembly. The outer peripheral side foil 321 and the inner peripheral side foil 322 are connected by the connecting portion 32f, whereby their mutual actions and deformations are not hindered.

[0089] As Figure 4 shown, the ridge line 321e in the outer peripheral side foil 321 extends obliquely in such a manner that it advances in the other direction around the axis as it advances from the inner peripheral side edge 321a of the outer peripheral side foil 321 toward the outer peripheral side. The ridge line 322e in the inner peripheral side foil 322 extends obliquely in such a manner that it advances in the other direction around the axis as it advances from the outer peripheral side edge 322a of the inner peripheral side foil 322 toward the inner peripheral side.

[0090] AsFigure 6 As shown, when the radial width of the outer peripheral foil 321 is set to Wout and the radial width of the inner peripheral foil 322 is set to Win, the relationship between the two becomes Wout = Win. Further, when the acute angle formed by the ridge line 321e in the outer peripheral foil 321 with respect to the radial direction is set to θout and the acute angle formed by the ridge line 322e in the inner peripheral foil 322 with respect to the radial direction is set to θin, the relationship between the two becomes θout = θin. In addition, the acute angle θout of the ridge line 321e in the outer peripheral foil 321 can also be said to be the inclination angle at which the ridge line 321e in the outer peripheral foil 321 inclines in the other direction around the axis. Similarly, the acute angle θin of the ridge line 322e in the inner peripheral foil 322 can also be said to be the inclination angle at which the ridge line 322e in the inner peripheral foil 322 inclines in the other direction around the axis.

[0091] Six top foils 33 are arranged at equal intervals in the circumferential direction of the rotating shaft 24a corresponding to the respective wave foils 32 on the end face on the side of the third support portion 24d of the bearing housing 31, and are arranged and mounted around the insertion through hole 31a. In each top foil 33, the end portion on the other side in the circumferential direction is bent toward the bearing housing 31, and its front end portion is fixed to the bearing housing 31 by welding. That is, the end portion on the other side in the circumferential direction of the top foil 33 is set as the fixed end 33a, and the end portion on one side in the circumferential direction is set as the free end 33b.

[0092] One radial foil bearing 40 is disposed in the first bearing holding portion 20, and the other radial foil bearing 40 is disposed in the second bearing holding portion 22. In the first bearing holding portion 20, the first support portion 24b of the rotating body 24 is supported by one radial foil bearing 40 so as to be rotatable. The outer peripheral surface of the first support portion 24b is provided with a radially supported bearing surface 24g that is supported by one radial foil bearing 40 in a direction orthogonal to the axial direction. In the second bearing holding portion 22, the second support portion 24c of the rotating body 24 is supported by the other radial foil bearing 40 so as to be rotatable. The outer peripheral surface of the second support portion 24c is provided with a radially supported bearing surface 24g that is supported by the other radial foil bearing 40 in a direction orthogonal to the axial direction.

[0093] Since the pair of radial foil bearings 40, 40 have substantially the same configuration, only the configuration of one radial foil bearing 40 will be described, and the description of the configuration of the other radial foil bearing 40 will be omitted.

[0094] The radial foil bearing 40 includes a radial bearing housing 41, a radial wave foil 42, and a radial top foil 43. Further, in one radial foil bearing 40, the first bearing holding portion 20 constitutes the radial bearing housing 41, and in the other radial foil bearing 40, the second bearing holding portion 22 constitutes the radial bearing housing 41.

[0095] Both the radial wave foil 42 and the radial top foil 43 are substantially cylindrical and are formed by shaping an elastic thin plate made of a metal such as stainless steel into a predetermined shape. The ends on the other side in the circumferential direction of the radial wave foil 42 and the radial top foil 43 are bent outward in the radial direction and fixed to the radial bearing housing 41. That is, in the radial wave foil 42 and the radial top foil 43, the ends on the other side in the circumferential direction are set as fixed ends, and the ends on one side in the circumferential direction are set as free ends.

[0096] The radial wave foil 42 has the following shape: a corrugated plate shape in which the ridges of the mountain portions protruding toward the radial top foil 43 are arranged in the circumferential direction of the rotation axis 24a. The radial wave foil 42 can elastically support the radial top foil 43 by using each mountain portion in a state where the radial wave foil 42 is supported by the radial bearing housing 41 at each valley portion disposed between adjacent mountain portions. In the radial top foil 43, the surface on the side opposite to the surface elastically supported by the radial wave foil 42 is set as a radial bearing surface 43a that faces the radial bearing surface 24g in the radial direction (see Figure 2 , Figure 3 ).

[0097] As Figure 7 shown, in a pair of thrust foil bearings 30, 30, before the rotational speed of the rotation axis 24a reaches the floating speed at which the third support portion 24d as a thrust ring floats through the thrust foil bearing 30, the rotation axis 24a is supported in a state where the bearing surface 33c of the top foil 33 is in contact with the bearing surface 241d of the third support portion 24d.

[0098] As Figure 8 shown, when the rotational speed of the rotation axis 24a reaches the floating speed, the third support portion 24d floats relative to the thrust foil bearing 30 due to the fluid film pressure generated between the third support portion 24d and the top foil 33. Thus, the thrust foil bearing 30 supports the rotation axis 24a in a non-contact state with the third support portion 24d.

[0099] Similarly, in a pair of radial foil bearings 40, 40, before the rotational speed of the rotation axis 24a reaches the floating speed at which the first support portion 24b and the second support portion 24c float through the radial foil bearing 40, the rotation axis 24a is supported in a state where the radial bearing surface 43a of the radial top foil 43 is in contact with the radial bearing surfaces 24g of the first support portion 24b and the second support portion 24c. When the rotational speed of the rotation axis 24a reaches the floating speed, the first support portion 24b and the second support portion 24c float relative to the radial foil bearing 40 due to the fluid film pressure generated between the first support portion 24b, the second support portion 24c and the radial top foil 43. Thus, the radial foil bearing 40 supports the rotation axis 24a in a non-contact state with the first support portion 24b and the second support portion 24c.

[0100] As Figures 1 to 3As shown, a cooling passage 50 is formed in the housing 11. Air as a fluid flows in the cooling passage 50. The cooling passage 50 is formed across the second plate 16, the first plate 15, the motor housing 12, and the third plate 17. The cooling passage 50 has a first passage 51 and a second passage 52.

[0101] The first passage 51 is provided in the second plate 16. The first passage 51 has an inlet 51a provided on the side wall surface of the second plate 16. The branch flow path L3 connects the supply flow path L1 and the inlet 51a of the first passage 51. The first passage 51 communicates with the motor chamber S1 via the thrust bearing housing chamber S2 and one of the radial foil bearings 40.

[0102] The second passage 52 is provided in the third plate 17. The second passage 52 has an outlet 52a provided on the side end surface of the third plate 17. The second passage 52 communicates with the motor chamber S1 via the other radial foil bearing 40.

[0103] In the first passage 51, a part of the air flowing in the supply flow path L1 toward the fuel cell stack 100 flows in via the branch flow path L3. In addition, the air flowing into the first passage 51 becomes cooling air by passing through the intercooler 110 in the middle of flowing in the branch flow path L3. The cooling air flowing into the first passage 51 flows into the thrust bearing housing chamber S2.

[0104] The cooling air flowing into the thrust bearing housing chamber S2 mainly flows from the inner peripheral side toward the outer peripheral side via one of the thrust foil bearings 30. Specifically, the cooling air flows from the inner peripheral side to the outer peripheral side between the top foil 33 of one of the thrust foil bearings 30 and the bearing housing 31. After passing through the outer side in the radial direction of the third support portion 24d as the thrust ring, the cooling air mainly flows from the outer peripheral side toward the inner peripheral side via the other thrust foil bearing 30. Specifically, the cooling air flows from the outer peripheral side to the inner peripheral side between the top foil 33 of the other thrust foil bearings 30 and the bearing housing 31.

[0105] The cooling air after passing through the thrust bearing housing chamber S2 flows into the motor chamber S1 via one of the radial foil bearings 40. Specifically, the cooling air flows from one side in the axial direction to the other side between the radial top foil 43 of one of the radial foil bearings 40 and the radial bearing housing 41. The cooling air after passing through the radial foil bearing 40 flows into the motor chamber S1.

[0106] The air flowing into the motor chamber S1, for example, passes between the rotor 36 and the stator 35, flows into the second passage 52 via the other radial foil bearing 40, and is discharged from the outlet 52a.

[0107] Thus, the electric motor 18, the pair of thrust foil bearings 30, 30, and the pair of radial foil bearings 40, 40 are directly cooled by the cooling air flowing through the cooling passage 50.

[0108] In this turbo compressor 10, the wave foil 32 in the thrust foil bearing 30 is divided in the radial direction of the rotating shaft 24a, and the inclination angle of the ridge line 32e of the mountain portion 32c in the corrugated plate shape is changed between the outer peripheral side foil 321 and the inner peripheral side foil 322. Specifically, the ridge line 321e in the outer peripheral side foil 321 extends obliquely in such a manner that it advances in the other direction around the axis as it advances from the inner peripheral edge 321a of the outer peripheral side foil 321 toward the outer peripheral side. On the other hand, the ridge line 322e in the inner peripheral side foil 322 extends obliquely in such a manner that it advances in the other direction around the axis as it advances from the outer peripheral edge 322a of the inner peripheral side foil 322 toward the inner peripheral side. That is, the ridge line 321e in the outer peripheral side foil 321 extends obliquely in such a manner that it advances toward the rear side in the rotation direction R as it advances from the inner peripheral side toward the outer peripheral side. On the other hand, the ridge line 322e in the inner peripheral side foil 322 extends obliquely in such a manner that it advances toward the rear side in the rotation direction R as it advances from the outer peripheral side toward the inner peripheral side.

[0109] In such a configuration, when the rotating shaft 24a rotates at a high speed equal to or higher than the floating speed, the ridge line of the mountain portion formed by transferring the corrugated plate shape of the wave foil 32 onto the top foil 33 becomes a so-called herringbone shape with the V-shaped top facing the front side in the rotation direction R, which is one direction around the axis. In this way, in the bearing clearance between the bearing surface 33c of the top foil 33 and the bearing surface 241d of the third support portion 24d serving as a thrust ring, the fluid guided by the herringbone-shaped ridge line is introduced toward the V-shaped top of the herringbone shape, that is, from the outer peripheral side and the inner peripheral side in the top foil 33 toward the radial center. Therefore, it is possible to suppress the leakage of the fluid compressed in the bearing clearance from the lateral sides of the outer peripheral side and the inner peripheral side in the bearing clearance, and it is possible to suppress the reduction of the fluid film pressure in the bearing clearance.

[0110] On the other hand, since no grooves are formed on the bearing surface 33c and the bearing surface 241d, when the rotating shaft 24a rotates at a low speed lower than the floating speed and the bearing surface 33c and the bearing surface 241d slide, the contact area between the bearing surface 33c and the bearing surface 241d does not decrease corresponding to the formation of grooves. Therefore, the durability of the top foil 33 is not reduced due to wear, sintering, etc.

[0111] Therefore, according to this turbo compressor 10, it is possible to suppress the reduction of the fluid film pressure in the thrust foil bearing 30 and thus suppress the reduction of the load capacity of the thrust foil bearing 30 without reducing the durability of the top foil 33.

[0112] In the thrust foil bearing 30, the heat resistance of the top foil 33 tends to be a problem. In this regard, in this turbo compressor 10, since the cooling air flows between the bearing housing 31 and the top foil 33, the top foil 33 can be cooled by the cooling air, and the problem of the heat resistance of the top foil 33 can be suppressed.

[0113] Similarly, in the radial foil bearing 40 as well, since the cooling air flows between the radial top foil 43 and the radial bearing housing 41, the radial top foil 43 can be cooled by the cooling air, and the problem of the heat resistance of the radial top foil 43 can be suppressed.

[0114] On the other hand, in the thrust foil bearing 30, in the case of the first passage 51 of the cooling passage 50 formed in such a manner that the cooling air flows between the bearing housing 31 and the top foil 33, the fluid leaked from the side of the bearing clearance flows out to the outside of the thrust bearing housing chamber S2 together with the cooling air via the first passage 51. Therefore, the leakage of the fluid from the side of the bearing clearance is directly related to the reduction of the fluid film pressure. Therefore, it becomes more important to suppress the leakage from the side of the bearing clearance. In this regard, in this turbo compressor 10, the case where the fluid in the bearing clearance can be suppressed from leaking from the side by the ridge line transferred to the mountain portion of the top foil 33 itself, so in the case of the first passage 51 of the cooling passage 50 formed as described above, the effect becomes remarkable.

[0115] In this turbo compressor 10, deformation examples 1 to 3 in which the shapes of the wave foils 32 of the thrust foil bearing 30 are respectively changed will be described below.

[0116] <Deformation Example 1 of the Wave Foil>

[0117] As Figure 9 shown, in the wave foil 32 according to the deformation example 1, the relationship between the radial width Wout of the outer peripheral side foil 321 and the radial width Win of the inner peripheral side foil 322 satisfies Wout > Win. In addition, the relationship between the acute angle θout of the ridge line 321e in the outer peripheral side foil 321 and the acute angle θin of the ridge line 322e in the inner peripheral side foil 322 is θout = θin.

[0118] In the thrust foil bearing 30, due to the action of the centrifugal force, the leakage of the fluid from the side of the bearing clearance is more on the outer peripheral side than on the inner peripheral side. In this regard, in the case of the above configuration, since the radial width Wout of the outer peripheral side foil 321 is larger than the radial width Win of the inner peripheral side foil 322, in the top foil 33, the force for effectively introducing the fluid that wants to leak to the side of the outer periphery due to the action of the centrifugal force to the center in the radial direction becomes larger, and the leakage of the fluid to the outer peripheral side can be effectively suppressed.

[0119] <Deformation Example 2 of the Wave Foil>

[0120] As Figure 10 shown, in the wave foil 32 according to the second modification, the relationship between the acute angle θout of the ridge line 321e in the outer peripheral foil 321 and the acute angle θin of the ridge line 322e in the inner peripheral foil 322 satisfies θout > θin. In addition, the relationship between the radial width Wout of the outer peripheral foil 321 and the radial width Win of the inner peripheral foil 322 is Wout = Win.

[0121] In this case, in the top foil 33, the force for effectively introducing the fluid that tends to leak laterally toward the outer periphery due to the action of the centrifugal force toward the center in the radial direction becomes larger, and the leakage of the fluid to the outer periphery can be effectively suppressed.

[0122] <Third Modification of the Wave Foil>

[0123] As Figure 11 shown, in the wave foil 32 according to the third modification, the outer peripheral foil 321 is further divided in the radial direction. That is, the outer peripheral foil 321 is divided in the radial direction into a first outer peripheral foil 323 disposed on the outer peripheral side and a second outer peripheral foil 324 disposed on the inner peripheral side. The relationship between the acute angle θout1 formed by the ridge line 323e in the first outer peripheral foil 323 with respect to the radial direction and the acute angle θout2 formed by the ridge line 324e in the second outer peripheral foil 324 with respect to the radial direction satisfies θout1 > θout2. In addition, the relationship between the acute angle θout1 of the ridge line 323e of the first outer peripheral foil 323, the acute angle θout2 of the ridge line 324e of the second outer peripheral foil 324, and the acute angle θin of the ridge line 322e of the inner peripheral foil 322 is θout1 > θin > θout2. Further, the relationship between the radial width Wout1 of the first outer peripheral foil 323, the radial width Wout2 of the second outer peripheral foil 324, and the radial width Win of the inner peripheral foil 322 becomes Wout1 > Wout2 > Win.

[0124] According to the above configuration, in the top foil 33, the force for introducing the fluid that tends to leak laterally toward the outer periphery due to the action of the centrifugal force toward the center becomes even larger, and the leakage of the fluid to the outer periphery can be more effectively suppressed.

[0125] As described above, the present invention has been described with reference to the embodiments, but the present invention is not limited to the above embodiments, and of course, it can be appropriately modified and applied without departing from the gist thereof.

[0126] For example, in the above embodiment, in the thrust foil bearing 30, six wave foils 32 and six top foils 33 are provided, but the number of the wave foils 32 and the top foils 33 is not limited thereto, and a plurality of the same number can be provided respectively.

[0127] In the above-described embodiment, in the thrust foil bearing 30, the outer peripheral foil 321 and the inner peripheral foil 322 are connected by the connecting portion 32f. However, the present invention is not limited thereto, and the outer peripheral foil 321 and the inner peripheral foil 322 may be disconnected.

[0128] In the above-described embodiment, in one of the thrust foil bearings 30, a part of the second plate 16 constituting the housing 11 is used as the bearing housing 31. In addition, in the other thrust foil bearing 30, a part of the first plate 15 constituting the housing 11 is used as the bearing housing 31. However, the present invention is not limited thereto. The bearing housing 31 of the thrust foil bearing 30 may be constituted by a component other than the components constituting the housing 11.

[0129]

Industrial Applicability

[0130] The present invention can be used for an air compressor or the like used in a fuel cell system.

[0131]

Explanation of Reference Numerals

[0132] 24a…Rotating shaft

[0133] 24d…Third supporting portion (thrust ring)

[0134] 241d…Bearing surface

[0135] 25…First impeller (working body)

[0136] 11…Housing

[0137] 30…Thrust foil bearing

[0138] 31…Bearing housing

[0139] 31a…Insertion through-hole

[0140] 32…Wave foil

[0141] 32c…Peak portion

[0142] 32e…Ridge line

[0143] 33…Top foil

[0144] 33c…Bearing surface

[0145] 50…Cooling passage

Claims

1. A turbo-type fluid machine, comprising: A rotating shaft that rotates in one direction around the axis; A plate-shaped thrust ring that is provided on the rotating shaft so as to extend from the circumferential surface to the radial direction and can rotate integrally with the rotating shaft; A working body that rotates integrally with the rotating shaft to pump an external fluid; A housing that houses the rotating shaft and the working body; and A thrust foil bearing that supports the rotating shaft in the axial direction of the rotating shaft so as to be rotatable relative to the housing, Characterized in that, The thrust foil bearing includes: a bearing housing having an insertion hole through which the rotating shaft is inserted and opposing the thrust ring in the axial direction; a plurality of wave foils that are arranged and mounted around the insertion hole on an end surface of the bearing housing on the thrust ring side; and a plurality of top foils that are formed of elastic thin plates having a bearing surface opposing the thrust ring on one side and elastically supported by each of the wave foils on the other side, The wave foil is formed of an elastic thin plate having a wave plate shape in which the ridge lines of the mountain portions protruding toward the thrust ring side are arranged in the circumferential direction of the rotating shaft, Each of the wave foils is divided in the radial direction of the rotating shaft into an outer peripheral side foil disposed on the outer peripheral side and an inner peripheral side foil disposed on the inner peripheral side, The ridge line in each of the outer peripheral side foils extends obliquely in such a manner that it travels in the other direction around the axis as it travels from the inner peripheral side edge of the outer peripheral side foil toward the outer peripheral side, The ridge line in each of the inner peripheral side foils extends obliquely in such a manner that it travels in the other direction around the axis as it travels from the outer peripheral side edge of the inner peripheral side foil toward the inner peripheral side.

2. The turbo-type fluid machine according to claim 1, The housing has a cooling passage through which a cooling fluid flows, and the cooling fluid is used to cool the thrust foil bearing, The cooling passage is formed in such a manner that the cooling fluid flows between the bearing housing and each of the top foils from the inner peripheral side of the top foil toward the outer peripheral side or from the outer peripheral side toward the inner peripheral side.

3. The turbo-type fluid machine according to claim 1 or 2, The relationship between the radial width Wout of the outer peripheral side foil and the radial width Win of the inner peripheral side foil satisfies Wout > Win.

4. The turbo-type fluid machine according to any one of claims 1 to 3, The relationship between the acute angle θout formed by the ridge line in the outer peripheral side foil with respect to the radial direction and the acute angle θin formed by the ridge line in the inner peripheral side foil with respect to the radial direction satisfies θout > θin.

5. The turbo-type fluid machine according to any one of claims 1 to 4, The outer peripheral side foil is divided in the radial direction into a first outer peripheral side foil disposed on the outer peripheral side and a second outer peripheral side foil disposed on the inner peripheral side, The relationship between the acute angle θout1 formed by the ridge line in the first outer peripheral side foil with respect to the radial direction and the acute angle θout2 formed by the ridge line in the second outer peripheral side foil with respect to the radial direction satisfies θout1 > θout2.

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