Centrifugal compressor

Abstract

To efficiently capture foreign matter contained in fluid and facilitate a replacement work of a filter while suppressing degradation of operation efficiency of a centrifugal compressor.SOLUTION: A mounting section 72 of a filter member 70 supports a filter 71 in an integrated state of the filter 71 and is mounted to be attachable / detachable to / from an opening wall section 48 forming an opening end part on a downstream side of a second discharge passage 47 in a housing 11. Therefore, attaching / detaching of the mounting section 72 to / from the housing 11 is facilitated. The filter member 70 has a through hole 73 extending on an axis line L10 of the second discharge passage 47. Therefore, air flowing on the axis line L10 of the second discharge passage 47 in the second discharge passage 47 passes the through hole 73. The filter 71 captures foreign matter contained in a swirl flow of air passing the second discharge passage 47. As a result, foreign matter contained in air passing the second discharge passage 47 is efficiently captured by the filter 71.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a centrifugal compressor. [Background technology]

[0002] A centrifugal compressor includes an impeller and a housing. The impeller rotates to compress a fluid. The housing defines an impeller chamber, an intake port, and a scroll passage. The impeller chamber accommodates the impeller. The intake port draws fluid into the impeller chamber. The scroll passage surrounds the impeller chamber in a spiral shape. The fluid compressed by the rotation of the impeller flows in a swirling manner in the scroll passage.

[0003] Incidentally, the fluid compressed by the rotation of the impeller may contain foreign matter. If the fluid contains foreign matter, it will be supplied to the destination of the supply of the fluid in a state where the foreign matter is contained in the fluid. Depending on the destination of the supply of the fluid, it may be undesirable to supply the fluid in a state where the foreign matter is contained in the fluid. Therefore, as in Patent Document 1, for example, it has been considered to supply the fluid to the destination after capturing the foreign matter contained in the fluid with a filter. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-125498 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, when such a filter is used in, for example, a centrifugal compressor, there is a risk that the discharge pressure of the centrifugal compressor will rise excessively if the filter becomes clogged. If the discharge pressure of the centrifugal compressor rises excessively, there is a risk that a surging phenomenon will occur due to a backflow of fluid in the impeller chamber. The surging phenomenon causes the impeller to vibrate, resulting in the generation of noise. Therefore, when such a filter is used, it is necessary to replace the filter with a new filter when the filter becomes clogged. For this reason, it is desirable to make the filter replacement work easier.

[0006] Furthermore, if a filter is used, pressure loss of the fluid occurs, which reduces the operating efficiency of the centrifugal compressor. Therefore, even if a filter is used, it is desirable to suppress the pressure loss of the fluid by preventing the flow of the fluid from being hindered by the filter as much as possible. It is also desirable to efficiently capture foreign matter contained in the fluid. In this way, it is desirable to efficiently capture foreign matter contained in the fluid while suppressing a decrease in the operating efficiency of the centrifugal compressor, and to make the filter replacement work easy. [Means for solving the problem]

[0007] A centrifugal compressor that solves the above problem includes an impeller that rotates to compress a fluid, an impeller chamber that accommodates the impeller, an intake port that draws fluid into the impeller chamber, and a housing that spirally surrounds the impeller chamber around the impeller chamber and defines a scroll passage through which the fluid compressed by the rotation of the impeller flows while swirling, and is equipped with a filter that captures foreign matter contained in the fluid, wherein the housing has a cylindrical discharge passage that communicates with the scroll passage and into which a swirling flow of the fluid that flows while swirling through the scroll passage flows, and is equipped with a filter member having the filter, the filter member having an attachment portion that supports the filter when the filter is integrated with the filter and is detachably attached to an opening wall portion that forms an open end portion of the housing on the downstream side of the discharge passage, and a through hole that extends on the axis of the discharge passage, and the filter captures foreign matter contained in the swirling flow that passes through the discharge passage.

[0008] According to this, the mounting portion of the filter member supports the filter in an integrated state and is detachably attached to the opening wall portion that forms the downstream open end of the discharge passage in the housing. This makes it easy to attach and detach the mounting portion to and from the housing. Therefore, for example, when the filter becomes clogged, the filter member can be removed from the housing simply by removing the mounting portion from the housing. This makes it easy to replace the clogged filter with a new filter, making the filter replacement work easy.

[0009] The filter member has a through hole extending along the axis of the discharge passage. With this, the fluid flowing through the discharge passage along the axis of the discharge passage passes through the through hole, so that even if a filter is used, the flow of the fluid is not hindered by the filter as much as possible. Therefore, the pressure loss of the fluid passing through the filter member can be suppressed. As a result, the decrease in the operating efficiency of the centrifugal compressor can be suppressed.

[0010] Since foreign matter in the fluid passing through the discharge passage tends to flow following the swirling flow of the fluid, the swirling flow of the fluid contains a relatively large amount of foreign matter. Therefore, the filter captures the foreign matter contained in the swirling flow of the fluid passing through the discharge passage. Therefore, the filter can efficiently capture the foreign matter contained in the fluid passing through the discharge passage. As a result, it is possible to efficiently capture the foreign matter contained in the fluid while suppressing a decrease in the operating efficiency of the centrifugal compressor, and also to facilitate the replacement work of the filter.

[0011] In the centrifugal compressor, the mounting portion may also serve as a pipe joint. According to this, since the mounting portion can function as a pipe joint, which is an existing configuration, there is no need to separately prepare a pipe joint and a mounting portion, and therefore the number of parts can be reduced, and the centrifugal compressor can be simplified in configuration.

[0012] In the above-mentioned centrifugal compressor, the mounting portion has a cylindrical portion that is inserted into the discharge passage and that constitutes a part of the through hole, and a communication hole that connects the inside and outside of the cylindrical portion is formed in the cylindrical portion, and the filter is arranged on the outer periphery of the cylindrical portion while covering the communication hole.

[0013] According to this, since the filter is disposed on the outer periphery of the cylindrical portion while covering the communication hole, foreign matter contained in the swirling flow of the fluid passing through the discharge passage can be efficiently captured by the filter. Then, after the foreign matter has been captured by the filter, the fluid passes through the communication hole and flows into the inside of the cylindrical portion, and passes through the through hole of the filter member. This configuration is suitable as a filter member having an attachment portion, a through hole, and a filter that captures foreign matter contained in the swirling flow of the fluid passing through the discharge passage.

[0014] In the above-mentioned centrifugal compressor, the communication holes may be formed in a plurality of parts in the cylindrical portion, the plurality of communication holes may be arranged at intervals in the circumferential direction of the cylindrical portion, and the filter may be annular and extend along the outer peripheral surface of the cylindrical portion.

[0015] According to this, since the filter is annular and extends along the outer peripheral surface of the cylindrical portion, even if a plurality of communication holes are formed in the cylindrical portion, each communication hole can be covered with one filter. Furthermore, since a plurality of communication holes are formed in the cylindrical portion, the fluid after foreign matter is captured by the filter can be efficiently flowed to the inside of the cylindrical portion through each communication hole. Therefore, foreign matter contained in the fluid can be captured more efficiently.

[0016] In the centrifugal compressor, the cylindrical portion may have a conical shape tapered in an insertion direction into the discharge passage. According to this, the fluid after the foreign matter is trapped by the filter smoothly flows into the communication hole, so that the pressure loss of the fluid can be easily suppressed. Therefore, the foreign matter contained in the fluid can be more efficiently trapped while further suppressing the decrease in the operating efficiency of the centrifugal compressor.

[0017] In the above-mentioned centrifugal compressor, the mounting portion has a plate-shaped flange portion extending along an opening end face located around the downstream opening of the discharge passage in the opening wall portion, the flange portion has a bolt insertion hole through which a bolt is inserted, and the opening end face has a female threaded hole through which the bolt is screwed, and the bolt inserted into the bolt insertion hole is screwed into the female threaded hole, whereby the mounting portion is detachably attached to the opening wall portion.

[0018] Such a configuration is suitable for a filter member having an attachment portion that is detachably attached to an opening wall portion that defines the downstream open end of the discharge passage in the housing.

[0019] In the centrifugal compressor described above, the fluid may be air supplied to a fuel cell stack, and the impeller may rotate to compress the air supplied to the fuel cell stack.

[0020] If air containing foreign matter is supplied to the fuel cell stack, the foreign matter will enter the fuel cell stack, which may reduce the power generation efficiency of the fuel cell stack. Therefore, by efficiently capturing the foreign matter contained in the air, the foreign matter is prevented from entering the fuel cell stack. As a result, the reduction in the power generation efficiency of the fuel cell stack can be reduced. Effect of the Invention

[0021] According to the present invention, it is possible to efficiently capture foreign matter contained in the fluid while suppressing a decrease in the operating efficiency of the centrifugal compressor, and to facilitate the replacement work of the filter. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is a cross-sectional view of a centrifugal compressor according to an embodiment. [Diagram 2] FIG. 2 is a cross-sectional view of a centrifugal compressor. [Diagram 3] FIG. 3 is a cross-sectional view of the filter member and the discharge pipe. [Figure 4] FIG. 4 is a perspective view of the mounting portion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Hereinafter, a centrifugal compressor according to one embodiment will be described with reference to Figures 1 to 4. The centrifugal compressor of this embodiment is mounted on a fuel cell vehicle. The centrifugal compressor compresses air as a fluid.

[0024] <Basic configuration of a centrifugal compressor> As shown in Fig. 1, the centrifugal compressor 10 includes a housing 11. The housing 11 is made of a metal material. For example, the housing 11 is made of aluminum. The housing 11 includes a motor housing 12, a first compressor housing 13, a second compressor housing 14, a first plate 15, a second plate 16, and a third plate 17.

[0025] The motor housing 12 has an end wall 12a and a peripheral wall 12b. The end wall 12a is plate-shaped. The peripheral wall 12b extends cylindrically from the outer periphery of the end wall 12a. The first plate 15 is connected to an end of the peripheral wall 12b of the motor housing 12 on the opening side. The first plate 15 closes the opening of the peripheral wall 12b of the motor housing 12. The motor housing 12 and the first plate 15 define a motor chamber 18. Thus, the housing 11 has the motor chamber 18.

[0026] The second plate 16 is connected to the outer surface of the end wall 12a of the motor housing 12. The second plate 16 is attached to the end wall 12a of the motor housing 12 with the thickness direction of the second plate 16 coinciding with the thickness direction of the end wall 12a of the motor housing 12.

[0027] The centrifugal compressor 10 includes a motor 20. The motor 20 is accommodated in the motor chamber 18. Thus, the motor chamber 18 accommodates the motor 20. The motor housing 12 surrounds the motor 20.

[0028] The centrifugal compressor 10 includes a first bearing retaining portion 21. The first bearing retaining portion 21 protrudes from the center of the first plate 15 into the motor chamber 18. Therefore, the first plate 15 has the first bearing retaining portion 21. The first bearing retaining portion 21 is cylindrical.

[0029] The third plate 17 is connected to the end face of the first plate 15 on the opposite side to the motor housing 12. The third plate 17 is attached to the first plate 15 with the thickness direction of the third plate 17 coinciding with the thickness direction of the first plate 15. The third plate 17 has a first insertion hole 23. The first insertion hole 23 is formed in the center of the third plate 17. The axis of the first insertion hole 23 coincides with the axis of the first bearing holder 21. The first insertion hole 23 communicates with the inside of the first bearing holder 21.

[0030] The centrifugal compressor 10 includes a second bearing retaining portion 25. The second bearing retaining portion 25 protrudes from the center of the end wall 12a of the motor housing 12 into the motor chamber 18. Therefore, the motor housing 12 has the second bearing retaining portion 25. The second bearing retaining portion 25 is cylindrical.

[0031] A second insertion hole 26 is formed in the second plate 16. The second insertion hole 26 penetrates the center of the second plate 16. The second insertion hole 26 communicates with the inside of the second bearing holder 25. The axis of the second insertion hole 26 coincides with the axis of the second bearing holder 25.

[0032] The first compressor housing 13 is cylindrical and has a first suction port 35 as a circular hole-shaped suction port through which air is drawn. The first compressor housing 13 is connected to an end face of the third plate 17 opposite to the first plate 15 with the axis of the first suction port 35 coinciding with the axis of the first insertion hole 23. The first suction port 35 is formed in the first compressor housing 13. The first suction port 35 opens to an end face of the first compressor housing 13 opposite to the third plate 17. Air cleaned by an air cleaner (not shown) flows through the first suction port 35.

[0033] The centrifugal compressor 10 includes a first impeller chamber 36 as an impeller chamber, a first scroll passage 37 as a scroll passage, and a first diffuser passage 38. The first impeller chamber 36, the first scroll passage 37, and the first diffuser passage 38 are formed between the first compressor housing 13 and the third plate 17. Therefore, the housing 11 partitions the first impeller chamber 36, the first suction port 35, and the first scroll passage 37. The first impeller chamber 36 is connected to the first suction port 35. The first scroll passage 37 spirally surrounds the first impeller chamber 36 around the first impeller chamber 36. The first scroll passage 37 extends around the axis of the first suction port 35. The first diffuser passage 38 connects the first impeller chamber 36 and the first scroll passage 37. The first impeller chamber 36 communicates with the first insertion hole 23 .

[0034] The housing 11 has a first discharge pipe 39. The first discharge pipe 39 protrudes from the outer peripheral surface of the first compressor housing 13. The first discharge pipe 39 is cylindrical. The housing 11 has a first discharge passage 40 as a discharge passage. The inside of the first discharge pipe 39 forms a part of the first discharge passage 40. In addition, a part of the first discharge passage 40 other than the inside of the first discharge pipe 39 is formed in the first compressor housing 13. The first discharge passage 40 is cylindrical. A first end of the first discharge passage 40 communicates with the first scroll passage 37. A second end of the first discharge passage 40 opens on a tip surface of the first discharge pipe 39. The second end of the first discharge passage 40 is an open end on the downstream side of the first discharge passage 40. Therefore, the tip of the first discharge pipe 39 is an opening wall portion 41 that forms an open end of the first discharge passage 40 in the housing 11.

[0035] The second compressor housing 14 is cylindrical and has a second suction port 42 as a circular hole-shaped suction port through which air is drawn. The second compressor housing 14 is connected to the end face of the second plate 16 opposite the end wall 12a of the motor housing 12 with the axis of the second suction port 42 coinciding with the axis of the second insertion hole 26. The second suction port 42 is formed in the second compressor housing 14. The second suction port 42 opens to the end face of the second compressor housing 14 opposite the second plate 16.

[0036] The centrifugal compressor 10 includes a second impeller chamber 43 as an impeller chamber, a second scroll passage 44 as a scroll passage, and a second diffuser passage 45. The second impeller chamber 43, the second scroll passage 44, and the second diffuser passage 45 are formed between the second compressor housing 14 and the second plate 16. Therefore, the housing 11 partitions the second impeller chamber 43, the second suction port 42, and the second scroll passage 44. The second impeller chamber 43 communicates with the second suction port 42. The second scroll passage 44 spirally surrounds the second impeller chamber 43 around the second impeller chamber 43. The second scroll passage 44 extends around the axis of the second suction port 42. The second diffuser passage 45 communicates the second impeller chamber 43 and the second scroll passage 44. The second impeller chamber 43 communicates with the second insertion hole 26 .

[0037] As shown in FIG. 2, the housing 11 has a second discharge pipe 46. The second discharge pipe 46 protrudes from the outer circumferential surface of the second compressor housing 14. The second discharge pipe 46 is cylindrical. The housing 11 has a second discharge passage 47 as a discharge passage. The inside of the second discharge pipe 46 forms a part of the second discharge passage 47. In addition, a part of the second discharge passage 47 other than the inside of the second discharge pipe 46 is formed in the second compressor housing 14. The second discharge passage 47 is cylindrical. A first end of the second discharge passage 47 communicates with the second scroll passage 44. A second end of the second discharge passage 47 opens on the tip surface of the second discharge pipe 46. The second end of the second discharge passage 47 is an open end on the downstream side of the second discharge passage 47. Therefore, the tip of the second discharge pipe 46 is an opening wall portion 48 that forms the open end of the second discharge passage 47 in the housing 11.

[0038] The tip surface of the second discharge pipe 46 is an opening end surface 48e located around the downstream opening of the second discharge passage 47 in the opening wall portion 48. The opening end surface 48e is flat. A plurality of female threaded holes 48h into which the bolts 65 are screwed are formed in the opening end surface 48e.

[0039] 1, a supply pipe 66 is connected to the second discharge pipe 46. The supply pipe 66 is connected to a fuel cell stack 67. A first end of the supply pipe 66 is connected to the second discharge passage 47. A second end of the supply pipe 66 is connected to the fuel cell stack 67.

[0040] The centrifugal compressor 10 includes a connecting pipe 68. A first end of the connecting pipe 68 is connected to the first discharge pipe 39. The first end of the connecting pipe 68 is connected to the first discharge passage 40. The second end of the connecting pipe 68 is connected to the second suction port 42. Air discharged from the first scroll passage 37 to the first discharge passage 40 flows through the connecting pipe 68. The air that has passed through the connecting pipe 68 is sucked into the second impeller chamber 43 through the second suction port 42.

[0041] The centrifugal compressor 10 includes a rotating shaft 50. The rotating shaft 50 crosses inside the motor chamber 18 with the axis of the rotating shaft 50 coinciding with the axis of the peripheral wall 12b of the motor housing 12. A first end, which is one end in the axial direction of the rotating shaft 50, protrudes from inside the motor chamber 18 to the inside of the first bearing holder 21, through the first insertion hole 23, and into the first impeller chamber 36. A second end, which is the other end in the axial direction of the rotating shaft 50, protrudes from inside the motor chamber 18 to the inside of the second bearing holder 25, through the second insertion hole 26, and into the second impeller chamber 43.

[0042] The motor 20 includes a rotor 51 and a stator 52. The rotor 51 is fixed to a rotating shaft 50. The rotor 51 has a cylindrical rotor core 53 fixed to the rotating shaft 50, and a plurality of permanent magnets (not shown) provided on the rotor core 53. The rotor 51 rotates integrally with the rotating shaft 50.

[0043] The stator 52 is fixed to the motor housing 12. The stator 52 is disposed outside the rotor 51. The stator 52 has a cylindrical stator core 54 and a coil 55. The stator core 54 is fixed to the inner circumferential surface of the peripheral wall 12b of the motor housing 12. The coil 55 is wound around the stator core 54. When a current flows from a battery (not shown) to the coil 55, the rotating shaft 50 rotates integrally with the rotor 51.

[0044] The centrifugal compressor 10 includes a first dynamic pressure plain bearing 56 and a second dynamic pressure plain bearing 57. The first dynamic pressure plain bearing 56 is cylindrical. The first dynamic pressure plain bearing 56 is held by the first bearing holder 21. The first dynamic pressure plain bearing 56 supports the rotating shaft 50 rotatably relative to the first plate 15.

[0045] The second dynamic pressure plain bearing 57 is cylindrical. The second dynamic pressure plain bearing 57 is held by the second bearing holder 25. The second dynamic pressure plain bearing 57 supports the rotating shaft 50 rotatably relative to the end wall 12a of the motor housing 12. Therefore, the first dynamic pressure plain bearing 56 and the second dynamic pressure plain bearing 57 support the rotating shaft 50 rotatably relative to the housing 11.

[0046] The centrifugal compressor 10 includes a first impeller 61 as an impeller. The centrifugal compressor 10 includes a second impeller 62 as an impeller. The first impeller 61 is connected to a first end of the rotating shaft 50. The first impeller 61 is housed in the first impeller chamber 36. Therefore, the first impeller chamber 36 houses the first impeller 61. The first impeller 61 rotates integrally with the rotating shaft 50. When the first impeller 61 rotates, air is sucked into the first impeller chamber 36 from the first suction port 35. Therefore, the first suction port 35 sucks air into the first impeller chamber 36. The first impeller 61 rotates integrally with the rotating shaft 50 to compress the air sucked into the first impeller chamber 36.

[0047] The second impeller 62 is connected to a second end of the rotating shaft 50. The second impeller 62 is housed in the second impeller chamber 43. Thus, the second impeller chamber 43 houses the second impeller 62. The second impeller 62 rotates integrally with the rotating shaft 50. When the second impeller 62 rotates, air is sucked into the second impeller chamber 43 from the second intake port 42. Thus, the second intake port 42 sucks air into the second impeller chamber 43. The second impeller 62 rotates integrally with the rotating shaft 50 to compress the air sucked into the second impeller chamber 43. The second impeller 62 compresses the air compressed by the first impeller 61. The first impeller 61 and the second impeller 62 rotate to compress the air supplied to the fuel cell stack 67. Therefore, the fluid compressed by the centrifugal compressor 10 of this embodiment is the air supplied to the fuel cell stack 67.

[0048] The first impeller 61 and the second impeller 62 rotate integrally with the rotary shaft 50 by being driven by the motor 20. Therefore, the motor 20 rotates the first impeller 61 and the second impeller 62.

[0049] The centrifugal compressor 10 includes a first seal member 63. The first seal member 63 is provided between the first insertion hole 23 and the rotating shaft 50. The first seal member 63 suppresses air leakage from the first impeller chamber 36 toward the inside of the motor chamber 18 via the first insertion hole 23 and the inside of the first bearing holder 21. The first seal member 63 is, for example, a seal ring.

[0050] The centrifugal compressor 10 includes a second seal member 64. The second seal member 64 is provided between the second insertion hole 26 and the rotating shaft 50. The second seal member 64 suppresses air leakage from the second impeller chamber 43 toward the inside of the motor chamber 18 via the second insertion hole 26 and the inside of the second bearing holder 25. The second seal member 64 is, for example, a seal ring.

[0051] The air drawn into the first impeller chamber 36 through the first intake port 35 is accelerated by the rotation of the first impeller 61 and is sent into the first diffuser passage 38, where it is pressurized by passing through the first diffuser passage 38. The air that has passed through the first diffuser passage 38 is then discharged into the first scroll passage 37. The air discharged into the first scroll passage 37 flows while swirling through the first scroll passage 37. Therefore, the air compressed by the rotation of the first impeller 61 flows while swirling through the first scroll passage 37. The air discharged into the first scroll passage 37 is discharged into the first discharge passage 40. The swirling flow of the air swirling through the first scroll passage 37 flows into the first discharge passage 40. The air discharged into the first discharge passage 40 is drawn into the second intake port 42 through the connecting pipe 68.

[0052] The air drawn into the second intake port 42 is drawn into the second impeller chamber 43. The air drawn into the second impeller chamber 43 is accelerated by the rotation of the second impeller 62 and sent into the second diffuser passage 45, where it is pressurized by passing through the second diffuser passage 45. The air that has passed through the second diffuser passage 45 is discharged into the second scroll passage 44. The air discharged into the second scroll passage 44 flows while swirling through the second scroll passage 44. Therefore, the air compressed by the rotation of the second impeller 62 flows while swirling through the second scroll passage 44. The air discharged into the second scroll passage 44 is discharged into the second discharge passage 47. As shown by the dashed arrow in FIG. 2, the swirling flow of the air swirling through the second scroll passage 44 flows into the second discharge passage 47. The air discharged into the second discharge passage 47 is supplied to the fuel cell stack 67 through the supply pipe 66. Therefore, the centrifugal compressor 10 supplies air to the fuel cell stack 67. The oxygen contained in the air supplied to the fuel cell stack 67 contributes to the power generation of the fuel cell stack 67.

[0053] <Filter material> 3, the centrifugal compressor 10 includes a filter member 70. The filter member 70 includes a filter 71, an attachment portion 72, and a through hole 73. Thus, the centrifugal compressor 10 includes the filter 71.

[0054] The mounting portion 72 is tubular. The mounting portion 72 has a main body portion 74, a tube portion 75, and a plate-shaped flange portion 76. The main body portion 74 is cylindrical. The outer diameter of the main body portion 74 is constant. The inside of the main body portion 74 forms a main body hole 77. The hole diameter of the main body hole 77 is constant. The main body hole 77 penetrates the main body portion 74 from the first end to the second end. The axis of the main body hole 77 coincides with the axis of the main body portion 74.

[0055] The cylindrical portion 75 extends from a first end of the main body portion 74. The cylindrical portion 75 is continuous with the first end of the main body portion 74. The cylindrical portion 75 has a conical shape that tapers as it moves away from the main body portion 74. The end of the cylindrical portion 75 opposite the main body portion 74 is open. The inside of the cylindrical portion 75 forms a conical hole 78. The conical hole 78 communicates with the first end of the main body hole 77. The axis of the conical hole 78 coincides with the axis of the main body hole 77.

[0056] As shown in Fig. 4, the mounting portion 72 has a pair of flange portions 76. Each flange portion 76 protrudes outward from a portion of the outer circumferential surface of the main body portion 74 that is located at a first end of the main body portion 74. The pair of flange portions 76 are disposed at positions spaced 180 degrees apart from each other in the circumferential direction of the main body portion 74. Each mounting portion 72 is flat. Each mounting portion 72 protrudes outward from the outer circumferential surface of the main body portion 74 with the thickness direction of each mounting portion 72 coinciding with the axial direction of the main body portion 74.

[0057] 3, the attachment portion 72 is disposed relative to the second discharge pipe 46 with each flange 76 extending along the opening end surface 48e located around the downstream opening of the second discharge passage 47 in the opening wall portion 48. Thus, each flange 76 extends along the opening end surface 48e.

[0058] A bolt insertion hole 79 is formed in each flange 76. A bolt 65 is inserted into each bolt insertion hole 79. Then, each bolt 65 inserted into each bolt insertion hole 79 is screwed into each female threaded hole 48h, whereby the mounting portion 72 is detachably attached to the opening wall portion 48 of the second discharge piping 46. Therefore, the mounting portion 72 is detachably attached to the opening wall portion 48.

[0059] When the mounting portion 72 is attached to the opening wall portion 48 of the second discharge pipe 46, the tubular portion 75 is inserted into the second discharge passage 47. Therefore, the tubular portion 75 is inserted into the second discharge passage 47. Therefore, the tubular portion 75 has a conical shape that tapers in the insertion direction Z1 in which the tubular portion 75 is inserted into the second discharge passage 47.

[0060] When the mounting portion 72 is attached to the opening wall portion 48 of the second discharge pipe 46, the axis of the main body hole 77 and the axis of the conical hole 78 coincide with the axis L10 of the second discharge passage 47. The through hole 73 is formed by the main body hole 77 and the conical hole 78. Therefore, the cylindrical portion 75 constitutes a part of the through hole 73. The through hole 73 extends on the axis L10 of the second discharge passage 47.

[0061] The attachment portion 72 has a retaining portion 80. The retaining portion 80 protrudes in an annular shape from a portion of the outer circumferential surface of the main body portion 74 that is located at the second end of the main body portion 74. Thus, the retaining portion 80 is provided at the end portion of the outer circumferential surface of the main body portion 74 opposite the tubular portion 75. The retaining portion 80 is hook-shaped.

[0062] As shown in Figs. 3 and 4, a communication hole 81 is formed in the cylindrical portion 75. A plurality of communication holes 81 are formed in the cylindrical portion 75. In this embodiment, four communication holes 81 are formed in the cylindrical portion 75. The plurality of communication holes 81 are arranged at intervals in the circumferential direction of the cylindrical portion 75. In detail, the four communication holes 81 are arranged at 90 degree intervals in the circumferential direction of the cylindrical portion 75. Each communication hole 81 communicates between the inside and the outside of the cylindrical portion 75. Each communication hole 81 is, for example, substantially trapezoidal hole-shaped.

[0063] As shown in FIG. 3, the filter 71 is, for example, a porous material configured to be able to capture foreign matter. The filter 71 is configured to allow air to pass through and to be able to capture foreign matter contained in the air. The filter 71 is annular. The filter 71 extends along the outer circumferential surface of the tubular portion 75. The filter 71 is disposed on the outer circumferential surface of the tubular portion 75 in a state in which the filter 71 covers each of the communication holes 81. The filter 71 is bonded to the outer circumferential surface of the tubular portion 75, for example, by an adhesive. Therefore, the attachment portion 72 supports the filter 71 in a state in which the filter 71 is integrated. The filter 71 is disposed between the outer circumferential surface of the tubular portion 75 and the inner circumferential surface of the second discharge pipe 46. The filter 71 is in close contact with the inner circumferential surface of the second discharge pipe 46. The filter 71 captures foreign matter contained in the swirling flow of air passing through the second discharge passage 47. Therefore, the filter 71 captures foreign matter contained in the air. The swirling flow of air passing through the second discharge passage 47 is indicated by dashed arrows in FIG.

[0064] A supply pipe 66 is connected to the main body 74 of the mounting part 72. The supply pipe 66 is, for example, a rubber hose. The supply pipe 66 is attached to the main body 74 in a state in which it surrounds the main body 74. The supply pipe 66 is attached to the main body 74 of the mounting part 72 in a state in which it is restrained by a restraining member 82. The restraining member 82 is, for example, a metal annular restraining band. The restraining member 82 is positioned closer to the tubular part 75 than the retaining portion 80 is to the main body 74. The retaining portion 80 prevents the restraining member 82 from coming off to the opposite side to the tubular part 75.

[0065] The attachment portion 72 functions as a pipe joint that relays the supply pipe 66 and the second discharge pipe 46. Therefore, the attachment portion 72 also serves as a pipe joint. In this manner, the supply pipe 66 is connected to the second discharge pipe 46 via the attachment portion 72.

[0066] [Operation of the embodiment] Next, the operation of the embodiment will be described. Foreign matter in the air passing through the second discharge passage 47 tends to flow following the swirling air flow, so the swirling air flow contains a relatively large amount of foreign matter. The filter 71 is disposed on the outer periphery of the tubular portion 75 while covering each of the communication holes 81. Therefore, foreign matter contained in the swirling air flow passing through the second discharge passage 47 is efficiently captured by the filter 71. Then, the air after the foreign matter has been captured by the filter 71 passes through each of the communication holes 81 and flows into the inside of the tubular portion 75, and passes through the through hole 73 of the filter member 70.

[0067] Further, the filter member 70 has a through hole 73 extending on the axis L10 of the second discharge passage 47. Therefore, the air flowing through the second discharge passage 47 on the axis L10 of the second discharge passage 47 passes through the through hole 73, so that even if the filter 71 is used, the flow of air is not hindered by the filter 71 as much as possible. Therefore, the pressure loss of the air passing through the filter member 70 is suppressed.

[0068] The air that has passed through the through holes 73 is supplied to the fuel cell stack 67 via the supply pipe 66. If the air containing foreign matter is supplied to the fuel cell stack 67, the foreign matter will enter the interior of the fuel cell stack 67, and there is a risk that the power generation efficiency of the fuel cell stack 67 will decrease. In this embodiment, the foreign matter contained in the air is efficiently captured, so that the foreign matter is prevented from entering the interior of the fuel cell stack 67. As a result, a decrease in the power generation efficiency of the fuel cell stack 67 is suppressed.

[0069] [Effects of the embodiment] The embodiment can provide the following effects. (1) The mounting portion 72 of the filter member 70 supports the filter 71 in an integrated state, and is detachably attached to the opening wall portion 48 that forms the downstream open end of the second discharge passage 47 in the housing 11. This makes it easy to attach and detach the mounting portion 72 to and from the housing 11. Therefore, for example, when the filter 71 becomes clogged, the filter member 70 can be removed from the housing 11 simply by removing the mounting portion 72 from the housing 11. This makes it easy to replace the clogged filter 71 with a new filter 71, making the replacement work of the filter 71 easy.

[0070] Moreover, the filter member 70 has a through hole 73 extending on the axis L10 of the second discharge passage 47. With this, the air flowing through the second discharge passage 47 on the axis L10 of the second discharge passage 47 passes through the through hole 73, so that even if the filter 71 is used, the flow of air is not hindered by the filter 71 as much as possible. Therefore, the pressure loss of the air passing through the filter member 70 can be suppressed. As a result, the decrease in the operating efficiency of the centrifugal compressor 10 can be suppressed.

[0071] Since foreign matter in the air passing through the second discharge passage 47 tends to flow following the swirling flow of the air, the swirling flow of the air contains a relatively large amount of foreign matter. Therefore, the filter 71 captures the foreign matter contained in the swirling flow of the air passing through the second discharge passage 47. Therefore, the filter 71 can efficiently capture the foreign matter contained in the air passing through the second discharge passage 47. As described above, it is possible to efficiently capture the foreign matter contained in the air while suppressing a decrease in the operating efficiency of the centrifugal compressor 10, and it is also possible to easily replace the filter 71.

[0072] (2) The mounting portion 72 also serves as a pipe joint. This allows the mounting portion 72 to function as a pipe joint, which is an existing configuration, and therefore eliminates the need to separately prepare a pipe joint and the mounting portion 72. This allows the number of parts to be reduced, and the centrifugal compressor 10 to have a simple configuration.

[0073] (3) Because the filter 71 is disposed on the outer periphery of the tubular portion 75 while covering the communication hole 81, foreign matter contained in the swirling flow of air passing through the second discharge passage 47 can be efficiently captured by the filter 71. Then, the air from which the foreign matter has been captured by the filter 71 passes through the communication hole 81 and flows into the inside of the tubular portion 75, and passes through the through hole 73 of the filter member 70. This configuration is suitable for the filter member 70, which has the attachment portion 72 and the through hole 73, and is provided with the filter 71 that captures foreign matter contained in the swirling flow of air passing through the second discharge passage 47.

[0074] (4) Because the filter 71 is annular and extends along the outer circumferential surface of the tubular portion 75, even if a plurality of communication holes 81 are formed in the tubular portion 75, each communication hole 81 can be covered with a single filter 71. Furthermore, because a plurality of communication holes 81 are formed in the tubular portion 75, the air after foreign matter has been captured by the filter 71 can efficiently flow into the inside of the tubular portion 75 through each communication hole 81. Therefore, foreign matter contained in the air can be captured even more efficiently.

[0075] (5) The cylindrical portion 75 has a conical shape tapered in the insertion direction Z1 into the second discharge passage 47. This allows the air after the foreign matter has been captured by the filter 71 to smoothly flow into the communication hole 81, making it easier to suppress air pressure loss. Therefore, it is possible to more efficiently capture foreign matter contained in the air while making it easier to further suppress a decrease in the operating efficiency of the centrifugal compressor 10.

[0076] (6) The bolts 65 inserted into the bolt insertion holes 79 are screwed into the female threaded holes 48h, whereby the mounting portion 72 is detachably attached to the opening wall portion 48. This configuration is preferable for the filter member 70 having the mounting portion 72 that is detachably attached to the opening wall portion 48 that forms the downstream opening end of the second discharge passage 47 in the housing 11.

[0077] (7) If air containing foreign matter is supplied to fuel cell stack 67, the foreign matter will enter the interior of fuel cell stack 67, which may reduce the power generation efficiency of fuel cell stack 67. Therefore, by efficiently capturing the foreign matter contained in the air, the foreign matter is prevented from entering the interior of fuel cell stack 67. As a result, the reduction in the power generation efficiency of fuel cell stack 67 can be reduced.

[0078] (8) For example, even if the filter 71 becomes clogged, the air flowing through the second discharge passage 47 on the axis L10 of the second discharge passage 47 passes through the through hole 73, so that the discharge pressure of the centrifugal compressor 10 is prevented from increasing excessively. This makes it possible to avoid a problem of surging caused by a backflow of air in the second impeller chamber 43. As a result, the vibration of the second impeller 62 is suppressed, and therefore noise can be suppressed.

[0079] [Example of change] The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other to the extent that no technical contradiction occurs.

[0080] In the embodiment, the attachment portion 72 does not have to function as a pipe joint. For example, the centrifugal compressor 10 may include the supply pipe 66, and the end of the supply pipe 66 on the side of the second discharge pipe 46 may serve as the attachment portion 72. In this case, a pipe joint separate from the attachment portion 72 may be provided between the attachment portion and the second discharge pipe 46, or a pipe joint may not be provided between the attachment portion and the second discharge pipe 46.

[0081] In the embodiment, for example, a mesh filter 71 may be attached to each communication hole 81. Each filter 71 is joined to each communication hole 81 so as to close the communication hole 81. Each filter 71 is joined to each communication hole 81 by, for example, spot welding. In this case, the mesh of the filter 71 is set to allow air to pass through and to capture foreign matter contained in the air.

[0082] In the embodiment, the number of communication holes 81 formed in the tubular portion 75 is not particularly limited. For example, only one communication hole 81 may be formed in the tubular portion 75. In this case, the filter 71 does not have to be annular extending along the outer circumferential surface of the tubular portion 75, and may be disposed, for example, in only a portion of the outer periphery of the tubular portion 75 while covering one communication hole 81.

[0083] In the embodiment, there is no particular limitation on the shape of the communication hole 81. The communication hole 81 may be, for example, a circular hole or a rectangular hole. In the embodiment, the tubular portion 75 does not need to taper in the insertion direction Z1 in which it is inserted into the second discharge passage 47, and the outer diameter may be constant. In this case, the outer diameter of the tubular portion 75 is smaller than the inner diameter of the second discharge pipe 46. The filter 71 can be disposed between the outer peripheral surface of the tubular portion 75 and the inner peripheral surface of the second discharge pipe 46.

[0084] In the above embodiment, the attachment portion 72 may be detachably attached to the opening wall portion 48 by, for example, pressing a press-fit pin that passes through the flange portion 76 into a hole provided in the opening wall portion 48 .

[0085] In the embodiment, the filter 71 may be provided, for example, on the inner circumferential surface of the main body portion 74. In this case, for example, an annular filter 71 is joined to the inner circumferential surface of the main body portion 74. The inside of the annular filter 71 forms a part of the through hole 73. In such a case, the attachment portion 72 may not have the cylindrical portion 75.

[0086] In the embodiment, for example, the housing 11 may not have the second discharge pipe 46. The second end of the second discharge passage 47 may open to the outer circumferential surface of the second compressor housing 14. In this case, a part of the outer circumferential surface of the second compressor housing 14 is an opening wall portion 48 that forms the open end of the second discharge passage 47. The part of the outer circumferential surface of the second compressor housing 14 surrounding the downstream opening of the second discharge passage 47 is an opening end surface 48e located around the downstream opening of the second discharge passage 47 in the opening wall portion 48.

[0087] In the above embodiment, the centrifugal compressor 10 may not include the second impeller 62. In this case, the attachment portion 72 of the filter member 70 is detachably attached to the opening wall portion 41 that defines the open end of the first discharge passage 40 in the housing 11.

[0088] In the above-mentioned embodiment, the centrifugal compressor 10 may be configured to include a turbine wheel instead of the second impeller 62. In this case, the attachment portion 72 of the filter member 70 is detachably attached to the opening wall portion 41 that defines the open end of the first discharge passage 40 in the housing 11.

[0089] In the above-mentioned embodiment, the centrifugal compressor 10 does not have to be mounted on a fuel cell vehicle. In other words, the centrifugal compressor 10 is not limited to being mounted on a vehicle. In the above-described embodiment, the centrifugal compressor 10 is not limited to be used for compressing the air supplied to the fuel cell stack 67. In short, the centrifugal compressor 10 may be used for compressing a fluid.

[0090] [Note] The above embodiment includes the configurations described in the following supplementary notes. <Appendix 1> an impeller that rotates to compress the fluid; an impeller chamber that accommodates the impeller, an intake port that draws fluid into the impeller chamber, and a housing that surrounds the impeller chamber in a spiral shape and defines a scroll flow passage through which fluid compressed by rotation of the impeller flows while swirling, A centrifugal compressor having a filter for capturing foreign matter contained in a fluid, The housing has a cylindrical discharge passage that is in communication with the scroll passage and into which a swirling flow of the fluid that flows while swirling through the scroll passage flows, a filter member having the filter, The filter member is a mounting portion that supports the filter in an integrated state and is detachably mounted to an opening wall portion that defines a downstream open end of the discharge passage in the housing; a through hole extending along an axis of the discharge passage, The centrifugal compressor according to claim 1, wherein the filter captures foreign matter contained in the swirling flow passing through the discharge passage.

[0091] <Appendix 2> The centrifugal compressor according to <Appendix 1>, wherein the mounting portion also serves as a pipe joint. <Appendix 3> the attachment portion has a cylindrical portion that is inserted into the discharge passage and that constitutes a part of the through hole, A communication hole is formed in the cylindrical portion to communicate between the inside and the outside of the cylindrical portion, The centrifugal compressor according to <Appendix 1> or <Appendix 2>, wherein the filter is disposed on an outer periphery of the cylindrical portion in a state where the communication hole is covered.

[0092] <Appendix 4> The communication hole is formed in a plurality of the cylindrical portion, The plurality of communication holes are arranged at intervals in a circumferential direction of the cylindrical portion, The centrifugal compressor according to <Appendix 3>, wherein the filter is annular and extends along an outer circumferential surface of the cylindrical portion.

[0093] <Appendix 5> The centrifugal compressor according to <Appendix 3> or <Appendix 4>, wherein the cylindrical portion has a conical shape tapered in an insertion direction into the discharge passage.

[0094] <Appendix 6> the attachment portion has a plate-shaped flange portion extending along an opening end surface located around the downstream opening of the opening wall portion of the discharge passage, The flange portion has a bolt insertion hole through which a bolt is inserted, A female threaded hole into which the bolt is screwed is formed in the opening end surface, The centrifugal compressor according to any one of <Appendix 1> to <Appendix 5>, characterized in that the mounting portion is detachably attached to the opening wall portion by the bolt inserted into the bolt insertion hole being screwed into the female threaded hole.

[0095] <Appendix 7> the fluid is air supplied to a fuel cell stack; The centrifugal compressor according to any one of <Appendix 1> to <Appendix 6>, wherein the impeller rotates to compress air to be supplied to the fuel cell stack. [Explanation of symbols]

[0096] 10...centrifugal compressor, 11...housing, 35...first suction port as suction port, 36...first impeller chamber as impeller chamber, 37...first scroll passage as scroll passage, 40...first discharge passage as discharge passage, 41...opening wall portion, 42...second suction port as suction port, 43...second impeller chamber as impeller chamber, 44...second scroll passage as scroll passage, 47...second discharge passage as discharge passage, 48...opening wall portion, 48e...opening end surface, 48h...female thread hole, 61...first impeller as impeller, 62...second impeller as impeller, 65...bolt, 67...fuel cell stack, 70...filter member, 71...filter, 72...mounting portion, 73...through hole, 75...tubular portion, 76...flange portion, 79...bolt insertion hole, 81...communicating hole.

Claims

1. an impeller that rotates to compress the fluid; an impeller chamber that accommodates the impeller, an intake port that draws fluid into the impeller chamber, and a housing that surrounds the impeller chamber in a spiral shape and defines a scroll flow passage through which fluid compressed by rotation of the impeller flows while swirling, A centrifugal compressor having a filter for capturing foreign matter contained in a fluid, The housing has a cylindrical discharge passage that is in communication with the scroll passage and into which a swirling flow of the fluid that flows while swirling through the scroll passage flows, a filter member having the filter, The filter member is a mounting portion that supports the filter in an integrated state and is detachably mounted to an opening wall portion that defines a downstream open end of the discharge passage in the housing; a through hole extending along an axis of the discharge passage, The centrifugal compressor according to claim 1, wherein the filter captures foreign matter contained in the swirling flow passing through the discharge passage.

2. 2. The centrifugal compressor according to claim 1, wherein the mounting portion also serves as a pipe joint.

3. the attachment portion has a cylindrical portion that is inserted into the discharge passage and that constitutes a part of the through hole, A communication hole is formed in the cylindrical portion to communicate between the inside and the outside of the cylindrical portion, 3. The centrifugal compressor according to claim 1, wherein the filter is disposed on an outer periphery of the cylindrical portion in a state where the filter covers the communication hole.

4. The communication hole is formed in a plurality of the cylindrical portion, The plurality of communication holes are arranged at intervals in a circumferential direction of the cylindrical portion, 4. The centrifugal compressor according to claim 3, wherein the filter is annular and extends along an outer circumferential surface of the cylindrical portion.

5. 4. The centrifugal compressor according to claim 3, wherein the cylindrical portion has a conical shape tapered in an insertion direction into the discharge passage.

6. the attachment portion has a plate-shaped flange portion extending along an opening end surface located around the downstream opening of the opening wall portion of the discharge passage, The flange portion has a bolt insertion hole through which a bolt is inserted, A female threaded hole into which the bolt is screwed is formed in the opening end surface, 2. The centrifugal compressor according to claim 1, wherein the mounting portion is detachably attached to the opening wall portion by the bolt being inserted into the bolt insertion hole and screwed into the female threaded hole.

7. the fluid is air supplied to a fuel cell stack; 2. The centrifugal compressor of claim 1, wherein the impeller rotates to compress air supplied to the fuel cell stack.

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