Centrifugal compressor

Abstract

The present application provides a centrifugal compressor, which improves the cooling performance for thrust bearings. A seal plate (17) has a cooling gas passage (G1) in its inside. Air cools the first and second thrust bearings (60, 61) and also cools the seal plate by flowing in the cooling gas passage (G1). Furthermore, the seal plate (17) has a cooling water passage (W1) in its inside. Cooling water flowing in the cooling water passage cools the seal plate. Therefore, the heat of air compressed by the compressor impeller (34) is difficult to transfer to the first and second thrust bearings housed in the thrust bearing housing chamber (S2) via the seal plate. Thus, the first and second thrust bearings are efficiently cooled by air. Furthermore, the heat of the first and second thrust bearings is dissipated to the cooling water flowing in the cooling water passage (W1).

Description

TECHNICAL FIELD

[0001] The present application relates to a centrifugal compressor. BACKGROUND

[0002] As a centrifugal compressor, for example, there is a centrifugal compressor described in Patent Literature 1. The centrifugal compressor has a rotation shaft and a compressor impeller. The compressor impeller is installed to the rotation shaft. The compressor impeller rotates integrally with the rotation shaft. The compressor impeller compresses fluid. The rotation shaft and the compressor impeller are housed in a casing of the centrifugal compressor. In addition, the centrifugal compressor has a thrust bearing. The thrust bearing rotatably supports the rotation shaft in a thrust direction.

[0003] The casing has an impeller chamber and a thrust bearing housing chamber. The compressor impeller is housed in the impeller chamber. The thrust bearing is housed in the thrust bearing housing chamber. In addition, the casing has a partition wall that separates the impeller chamber from the thrust bearing housing chamber.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent Application Publication No. 2019-127898 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] The fluid compressed by the compressor impeller has a higher temperature than before compression. Also, when the heat of the compressed fluid is transferred to the thrust bearing housed in the thrust bearing housing chamber via the partition wall, the temperature of the thrust bearing becomes high, so the durability of the thrust bearing deteriorates. Therefore, it is required to improve the cooling performance for the thrust bearing.

[0009] TECHNICAL SOLUTION TO THE PROBLEM

[0010] A centrifugal compressor that solves the above problem has a rotation shaft, a compressor impeller installed to the rotation shaft and compressing fluid by rotating integrally with the rotation shaft, a casing housing the rotation shaft and the compressor impeller, and a thrust bearing rotatably supporting the rotation shaft in a thrust direction, the casing having an impeller chamber housing the compressor impeller, a thrust bearing housing chamber housing the thrust bearing, and a partition wall separating the impeller chamber from the thrust bearing housing chamber, the partition wall having, inside the partition wall, a cooling gas passage through which cooling gas for cooling the thrust bearing flows, and a cooling water passage through which cooling water for cooling the partition wall flows.

[0011] Accordingly, the partition wall has a cooling gas passage inside the partition wall. Therefore, the cooling gas can cool the thrust bearing and also cool the partition wall by flowing in the cooling gas passage. Also, the partition wall has a cooling water passage inside the partition wall, so the partition wall can be further cooled by the cooling water. Therefore, the heat of the fluid compressed by the compressor impeller is less likely to be transmitted to the thrust bearing housed in the thrust bearing housing chamber via the partition wall. Thus, the thrust bearing can be efficiently cooled by the cooling gas. Also, the heat of the thrust bearing is dissipated to the cooling water flowing in the cooling water passage. Therefore, the cooling performance for the thrust bearing can be improved.

[0012] In the centrifugal compressor described above, the cooling water passage can be located at a position radially outward of the cooling gas passage with respect to the rotation axis.

[0013] Accordingly, compared to the case where the cooling water passage is located at a position radially inward of the cooling gas passage with respect to the rotation axis, the surface area of the cooling water passage can be increased. Therefore, the partition wall can be efficiently cooled. Thus, the heat of the fluid compressed by the compressor impeller is even less likely to be transmitted to the thrust bearing housed in the thrust bearing housing chamber via the partition wall. Also, the heat of the thrust bearing is even more likely to be dissipated to the cooling water flowing in the cooling water passage. As a result, the cooling performance for the thrust bearing can be further improved.

[0014] Effects of Invention

[0015] According to the present application, the cooling performance for the thrust bearing can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a side sectional view showing a centrifugal compressor in an embodiment.

[0017] Figure 2 is a side sectional view showing a part of the centrifugal compressor in an enlarged manner.

[0018] Figure 3 is a front view showing a seal plate. DETAILED DESCRIPTION

[0019] Hereinafter, an embodiment in which the centrifugal compressor is embodied will be described. Figures 1-3 An embodiment in which the centrifugal compressor is embodied will be described. The centrifugal compressor of the present embodiment is mounted on a fuel cell vehicle.

[0020] <Overall Configuration of Centrifugal Compressor 10>

[0021] As shown in FIG. 1, the centrifugal compressor 10 includes a housing 12, a seal plate 14, a rotor 16, a thrust bearing 18, a thrust bearing housing chamber 20, a cooling water passage 22, and a cooling gas passage 24. Figure 1As shown, the centrifugal compressor 10 is provided with a casing 11. The casing 11 is made of a metal material, for example, aluminum. The casing 11 has a motor casing 12, a compressor casing 13, a turbine casing 14, a first plate 15, a second plate 16, and a seal plate 17.

[0022] The motor casing 12 is cylindrical. The motor casing 12 has an end wall 12a and a peripheral wall 12b which are plate-shaped. The peripheral wall 12b extends in a cylindrical shape from the outer peripheral portion of the end wall 12a. The first plate 15 is joined to the end portion of the peripheral wall 12b of the motor casing 12 on the opening side. The first plate 15 closes the opening of the peripheral wall 12b of the motor casing 12. Further, a motor chamber S1 is partitioned by the end wall 12a and the peripheral wall 12b of the motor casing 12 and the first plate 15. The motor chamber S1 houses an electric motor 40.

[0023] As shown, the centrifugal compressor 10 is provided with a casing 11. The casing 11 is made of a metal material, for example, aluminum. The casing 11 has a motor casing 12, a compressor casing 13, a turbine casing 14, a first plate 15, a second plate 16, and a seal plate 17. Figure 2 As shown, the centrifugal compressor 10 is provided with a casing 11. The casing 11 is made of a metal material, for example, aluminum. The casing 11 has a motor casing 12, a compressor casing 13, a turbine casing 14, a first plate 15, a second plate 16, and a seal plate 17.

[0024] The first plate 15 has a first bearing holding portion 20. The first bearing holding portion 20 is cylindrical. The first bearing holding portion 20 protrudes from the central portion of the end face 15b of the first plate 15 toward the electric motor 40. The first bearing holding portion 20 is opened through the first plate 15 at the bottom face 15h of the second recessed portion 15d. The axis of the first bearing holding portion 20 coincides with the axes of the first recessed portion 15c and the second recessed portion 15d.

[0025] As shown, the centrifugal compressor 10 is provided with a casing 11. The casing 11 is made of a metal material, for example, aluminum. The casing 11 has a motor casing 12, a compressor casing 13, a turbine casing 14, a first plate 15, a second plate 16, and a seal plate 17. Figure 1 As shown, the centrifugal compressor 10 is provided with a casing 11. The casing 11 is made of a metal material, for example, aluminum. The casing 11 has a motor casing 12, a compressor casing 13, a turbine casing 14, a first plate 15, a second plate 16, and a seal plate 17.

[0026] The second plate 16 is joined to the outer surface 122a of the end wall 12a of the motor casing 12. A shaft insertion hole 16a is formed in the central portion of the second plate 16. The shaft insertion hole 16a communicates with the inner side of the second bearing holding portion 21. The axis of the shaft insertion hole 16a coincides with the axis of the second bearing holding portion 21.

[0027] As shown in Figure 2 the central portion of the seal plate 17 is formed with a shaft insertion hole 17a. The shaft center of the shaft insertion hole 17a coincides with the shaft center of the first bearing holding portion 20. The seal plate 17 has a plurality of bolt insertion holes 17h through which the bolts B1 are inserted. The plurality of bolt insertion holes 17h are arranged at intervals in the outer peripheral portion of the seal plate 17 around the shaft insertion hole 17a. Further, in Figure 2 the one of the plurality of bolt insertion holes 17h is illustrated. Each of the bolt insertion holes 17h is a circular hole. Also, the seal plate 17 is attached to the first plate 15 by the bolts B1 inserted into each of the bolt insertion holes 17h being screwed into the first plate 15 in a state of being fitted into the first recessed portion 15c. The seal plate 17 closes the opening of the second recessed portion 15d. Also, a thrust bearing housing chamber S2 is demarcated by the end surface 17b of the seal plate 17 close to the first plate 15 and the second recessed portion 15d of the first plate 15.

[0028] The compressor housing 13 is cylindrical. The compressor housing 13 has a suction port 13a which is a circular hole. The compressor housing 13 is joined to the end surface 15a of the first plate 15 in a state where the shaft center of the suction port 13a coincides with the shaft center of the shaft insertion hole 17a of the seal plate 17 and the shaft center of the first bearing holding portion 20. The suction port 13a opens to the end surface of the compressor housing 13 on the side opposite to the first plate 15.

[0029] Between the compressor housing 13 and the seal plate 17, a impeller chamber 13b, a discharge chamber 13c, and a first diffusion flow path 13d are formed. Therefore, the seal plate 17 functions as a partition wall that separates the impeller chamber 13b from the thrust bearing housing chamber S2. The impeller chamber 13b communicates with the suction port 13a. The discharge chamber 13c extends around the shaft center of the suction port 13a from the impeller chamber 13b. The first diffusion flow path 13d communicates the impeller chamber 13b with the discharge chamber 13c. The impeller chamber 13b communicates with the shaft insertion hole 17a of the seal plate 17.

[0030] As shown in Figure 1 the turbine housing 14 is cylindrical. The turbine housing 14 has a discharge port 14a which is a circular hole. The turbine housing 14 is joined to the end surface 16b of the second plate 16 on the side opposite to the motor housing 12 in a state where the shaft center of the discharge port 14a coincides with the shaft center of the shaft insertion hole 16a of the second plate 16 and the shaft center of the second bearing holding portion 21. The discharge port 14a opens to the end surface of the turbine housing 14 on the side opposite to the second plate 16.

[0031] Between the turbine housing 14 and the end surface 16b of the second plate 16, a turbine chamber 14b, a suction chamber 14c, and a second diffusion flow path 14d are formed. The turbine chamber 14b communicates with the discharge port 14a. The suction chamber 14c extends around the axis of the discharge port 14a in the turbine chamber 14b. The second diffusion flow path 14d communicates the turbine chamber 14b with the suction chamber 14c. The turbine chamber 14b communicates with the shaft insertion hole 16a.

[0032] <Configuration of the rotating body A1>

[0033] The centrifugal compressor 10 is provided with a rotating body A1. The rotating body A1 has a rotating shaft 30, a first support portion 31, a second support portion 32, and a support plate 33. Thus, the centrifugal compressor 10 is provided with the rotating shaft 30. The rotating shaft 30, the first support portion 31, the second support portion 32, and the support plate 33 are housed in the housing 11.

[0034] The rotating shaft 30 is housed in the housing 11 in a state in which the axis direction of the rotating shaft 30 coincides with the axis direction of the motor housing 12. The first end portion 30a of the rotating shaft 30 protrudes into the impeller chamber 13b from the motor chamber S1 through the inside of the first bearing holding portion 20, the thrust bearing housing chamber S2, and the shaft insertion hole 17a. The second end portion 30b of the rotating shaft 30 protrudes into the turbine chamber 14b from the motor chamber S1 through the inside of the second bearing holding portion 21 and the shaft insertion hole 16a.

[0035] A first seal member 22 is provided between the shaft insertion hole 17a of the seal plate 17 and the rotating shaft 30. The first seal member 22 suppresses leakage of air from the impeller chamber 13b to the motor chamber S1. A second seal member 23 is provided between the shaft insertion hole 16a of the second plate 16 and the rotating shaft 30. The second seal member 23 suppresses leakage of air from the turbine chamber 14b to the motor chamber S1. The first seal member 22 and the second seal member 23 are, for example, seal rings.

[0036] The first support portion 31 is provided at a portion of the outer peripheral surface 300 of the rotating shaft 30 close to the first end portion 30a. The first support portion 31 is disposed inside the first bearing holding portion 20. The first support portion 31 is integrally formed with the rotating shaft 30. The first support portion 31 protrudes from the outer peripheral surface 300 of the rotating shaft 30.

[0037] The second support portion 32 is provided at a portion of the outer peripheral surface 300 of the rotating shaft 30 close to the second end portion 30b. The second support portion 32 is disposed inside the second bearing holding portion 21. The second support portion 32 is fixed to the outer peripheral surface 300 of the rotating shaft 30 in a state in which the second support portion 32 protrudes in a ring shape from the outer peripheral surface 300 of the rotating shaft 30. The second support portion 32 is rotatable integrally with the rotating shaft 30.

[0038] The support plate 33 is housed in the thrust bearing housing chamber S2. The support plate 33 is fixed to the outer peripheral surface 300 of the rotary shaft 30 in a state of projecting in a radial direction outward from the outer peripheral surface 300 of the rotary shaft 30. Therefore, the support plate 33 is separate from the rotary shaft 30. The support plate 33 is rotatable integrally with the rotary shaft 30.

[0039] <Regarding the compressor impeller 34>

[0040] The centrifugal compressor 10 is provided with the compressor impeller 34. The compressor impeller 34 is attached to the first end portion 30a of the rotary shaft 30 in the axial direction. The compressor impeller 34 is disposed in the rotary shaft 30 at a position closer to the first end portion 30a than the support plate 33. The compressor impeller 34 is housed in the impeller chamber 13b. Therefore, the casing 11 has the impeller chamber 13b that houses the compressor impeller 34. Thus, the casing 11 houses the rotary shaft 30 and the compressor impeller 34. Therefore, the centrifugal compressor 10 is provided with the casing 11 that houses the rotary shaft 30 and the compressor impeller 34. The compressor impeller 34 rotates integrally with the rotary shaft 30.

[0041] <Regarding the turbine wheel 35>

[0042] The centrifugal compressor 10 is provided with the turbine wheel 35. The turbine wheel 35 is attached to the second end portion 30b of the rotary shaft 30. The turbine wheel 35 is disposed in the rotary shaft 30 at a position closer to the second end portion 30b than the second support portion 32. The turbine wheel 35 is housed in the turbine chamber 14b. The turbine wheel 35 rotates integrally with the rotary shaft 30.

[0043] <Configuration of the electric motor 40>

[0044] The electric motor 40 is provided with a cylindrical rotor 41 and a cylindrical stator 42. The rotor 41 is fixed to the rotary shaft 30. The stator 42 is fixed to the casing 11. The rotor 41 is disposed radially inward of the stator 42 and rotates integrally with the rotary shaft 30. The rotor 41 has a cylindrical rotor core 41a fixedly attached to the rotary shaft 30 and a plurality of permanent magnets (not shown) provided to the rotor core 41a. The stator 42 surrounds the rotor 41. The stator 42 has a cylindrical stator core 43 fixed to an inner peripheral surface 121b of the peripheral wall 12b of the motor casing 12 and a coil 44 wound around the stator core 43. The rotary shaft 30 rotates integrally with the rotor 41 by a current flowing from a battery (not shown) to the coil 44. Therefore, the electric motor 40 rotates the rotary shaft 30. The electric motor 40 is disposed between the compressor impeller 34 and the turbine wheel 35 in the axial direction of the rotary shaft 30.

[0045] <Regarding the first and second radial bearings 50 and 51>

[0046] The centrifugal compressor 10 is provided with a first radial bearing 50 and a second radial bearing 51. The first radial bearing 50 is cylindrical. The first radial bearing 50 is held by the first bearing holding portion 20. The second radial bearing 51 is cylindrical. The second radial bearing 51 is held by the second bearing holding portion 21. The first radial bearing 50 and the second radial bearing 51 support the rotating shaft 30 in a radial direction so as to be rotatable with respect to the casing 11. Further, the "radial direction" refers to a direction orthogonal to the axial direction of the rotating shaft 30.

[0047] <Regarding the first thrust bearing 60 and the second thrust bearing 61>

[0048] As shown in FIG. 1, the centrifugal compressor 10 is provided with a first thrust bearing 60 and a second thrust bearing 61 as thrust bearings. The first thrust bearing 60 and the second thrust bearing 61 support the support plate 33 in a thrust direction so as to be rotatable with respect to the casing 11. Further, the "thrust direction" refers to a direction parallel to the axial direction of the rotating shaft 30. Figure 2

[0049] The first thrust bearing 60 and the second thrust bearing 61 are accommodated in a thrust bearing accommodation chamber S2. Therefore, the casing 11 has the thrust bearing accommodation chamber S2 that accommodates the first thrust bearing 60 and the second thrust bearing 61. The first thrust bearing 60 and the second thrust bearing 61 are arranged so as to sandwich the support plate 33. The second thrust bearing 61 and the support plate 33 are arranged between the compressor impeller 34 and the first thrust bearing 60. The second thrust bearing 61 is arranged between the compressor impeller 34 and the support plate 33. The first thrust bearing 60 has a first thrust bearing body portion 60a and a first base portion 60b. The first base portion 60b is a circular plate. A first through-hole 60c through which the rotating shaft 30 passes is formed in the first base portion 60b. The second thrust bearing 61 has a second thrust bearing body portion 61a and a second base portion 61b. The second base portion 61b is a circular plate. A second through-hole 61c through which the rotating shaft 30 passes is formed in the second base portion 61b.

[0050] <Regarding the fuel cell system 1>

[0051] As shown in FIG. 1, the centrifugal compressor 10 configured as described above constitutes a part of a fuel cell system 1 mounted on a fuel cell vehicle. The fuel cell system 1 is provided with, in addition to the centrifugal compressor 10, a fuel cell stack 100, a supply flow path L1, a discharge flow path L2, and a branch flow path L3. The fuel cell stack 100 is configured of a plurality of cell units. Further, the illustration of each cell unit is omitted for convenience of explanation. 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. Figure 1

[0052] ​​When the rotating shaft 30 rotates integrally with the rotor 41, the compressor impeller 34 and the turbine impeller 35 rotate integrally with the rotating shaft 30. Thus, air drawn in from the suction port 13a is compressed by the compressor impeller 34 within the impeller chamber 13b and discharged from the discharge chamber 13c via the first diffuser path 13d. Therefore, the compressor impeller 34 compresses air by rotating integrally with the rotating shaft 30.

[0053] Furthermore, air discharged from exhaust chamber 13c is supplied to fuel cell stack 100 via supply flow path L1. The air supplied to fuel cell stack 100 is used to generate electricity. Afterward, the air passing through fuel cell stack 100 is discharged as exhaust gas to exhaust flow path L2. The exhaust gas from fuel cell stack 100 is drawn into intake chamber 14c via exhaust flow path L2. The exhaust gas from fuel cell stack 100 drawn into intake chamber 14c is introduced into turbine chamber 14b via second diffusion flow path 14d. Turbine impeller 35 rotates due to the exhaust gas from fuel cell stack 100 introduced into turbine chamber 14b. Rotation shaft 30 rotates not only by the drive of electric motor 40 but also by the rotation of turbine impeller 35, which rotates due to the exhaust gas from fuel cell stack 100. Furthermore, the rotation of turbine impeller 35, based on the exhaust gas from fuel cell stack 100, assists in the rotation of rotation shaft 30. The exhaust gas after passing through turbine chamber 14b is discharged to the outside from exhaust port 14a.

[0054] <Regarding cooling gas passage G1 and the air flowing in cooling gas passage G1>

[0055] like Figure 2 and Figure 3 As shown, a recess 17c is formed in the center of the end face 17b of the sealing plate 17. The recess 17c is circular. Most of the opening of the recess 17c is closed by the second base portion 61b. Furthermore, a cooling gas passage G1 is defined by the recess 17c of the sealing plate 17 and the second base portion 61b. The cooling gas passage G1 is connected to the thrust bearing housing S2 via the second through hole 61c of the second base portion 61b and the rotating shaft 30.

[0056] A connecting hole 17e and a connecting passage G2 are formed in the sealing plate 17. The connecting hole 17e is circular. The connecting hole 17e opens at the end face 17b of the sealing plate 17. The connecting passage G2 connects the recess 17c to the connecting hole 17e. The connecting passage G2 extends radially outward from the cooling gas passage G1 toward the rotating shaft 30.

[0057] Further, a through-hole 15i is formed in the first plate 15. The through-hole 15i penetrates the first plate 15 in the thickness direction. The axis of the communication hole 17e coincides with the axis of the through-hole 15i. One end of the through-hole 15i communicates with the communication hole 17e. The other end of the through-hole 15i communicates with the motor chamber S1. Thus, the communication hole 17e communicates with the motor chamber S1 via the through-hole 15i. In this way, the cooling gas passage G1 communicates with the motor chamber S1 via the connection passage G2, the communication hole 17e, and the through-hole 15i.

[0058] In the cooling gas passage G1, cooling gas that cools the first and second thrust bearings 60 and 61 flows. Specifically, a first flow path 71 is formed in the first plate 15. The first flow path 71 extends in the radial direction of the rotary shaft 30. One end of the first flow path 71 opens to the outer surface of the first plate 15. The other end of the first flow path 71 communicates with the thrust bearing accommodation chamber S2. Further, a second flow path 72 is formed in the second plate 16. The second flow path 72 extends in the radial direction of the rotary shaft 30. One end of the second flow path 72 opens to the outer surface of the second plate 16. The other end of the second flow path 72 communicates with a portion of the shaft insertion hole 16a that is closer to the motor housing 12 than the second seal member 23.

[0059] Further, a branch flow path L3 branches from the supply flow path L1. The branch flow path L3 connects the supply flow path L1 and the first flow path 71. A middle cooler R1 is provided midway through the branch flow path L3. The middle cooler R1 cools air flowing in the branch flow path L3.

[0060] A portion of the air that is compressed by the compressor impeller 34 and flows in the supply flow path L1 toward the fuel cell stack 100 flows into the first flow path 71 via the branch flow path L3. Further, the air that flows into the first flow path 71 is cooled by the middle cooler R1 midway through the branch flow path L3. The air that flows into the first flow path 71 flows into the thrust bearing accommodation chamber S2, cooling the first and second thrust bearings 60 and 61. Thus, the cooling gas that cools the first and second thrust bearings 60 and 61 is a portion of the air that is compressed by the compressor impeller 34.

[0061] Further, the air in the thrust bearing accommodation chamber S2 flows into the cooling gas passage G1 via the second through-hole 61c of the second base portion 61b and the rotary shaft 30. The air that flows into the cooling gas passage G1 flows into the motor chamber S1 via the communication hole 17e and the through-hole 15i through the connection passage G2.

[0062] The electric motor 40 is cooled by air flowing into the motor chamber S1. Additionally, a portion of the air flowing into the motor chamber S1 flows between the first radial bearing 50 and the first support portion 31, cooling the first radial bearing 50. Furthermore, the air flowing into the motor chamber S1 passes, for example, between the rotor 41 and the stator 42 and flows between the second radial bearing 51 and the second support portion 32, cooling the second radial bearing 51. Next, the air that has passed between the second radial bearing 51 and the second support portion 32 is discharged to the outside of the housing 11 through the shaft insertion hole 16a and the second flow path 72.

[0063] <Regarding cooling water passage W1>

[0064] A groove 17d is formed on the end face 17b of the sealing plate 17. The groove 17d extends circumferentially toward the rotation shaft 30 from the end face 17b of the sealing plate 17, surrounding the recess 17c radially outward from the rotation shaft 30. The groove 17d meanders around the axis of the shaft insertion hole 17a. Specifically, the groove 17d is formed such that portions extending close to the axis of the shaft insertion hole 17a alternately extend away from the axis of the shaft insertion hole 17a. The groove 17d extends circumferentially toward the rotation shaft 30 relative to each bolt insertion hole 17h, passing radially inward from the rotation shaft 30. The first end 170d and the second end 171d of the groove 17d are configured such that the groove 17d extends over almost the entire circumferential area of ​​the sealing plate 17. The opening of the groove 17d is closed by the first plate 15. Furthermore, a cooling water passage W1 is defined by the groove 17d and the bottom surface 15f of the first recess 15c of the first plate 15. Thus, the cooling water passage W1 is located radially outward from the rotation axis 30 compared to the cooling gas passage G1. Additionally, a sealing member (not shown) is provided between the end face 17b of the sealing plate 17 and the bottom surface 15f of the first recess 15c of the first plate 15 to suppress leakage of cooling water flowing in the cooling water passage W1.

[0065] like Figure 1 As shown, the centrifugal compressor 10 includes a cooling water jacket 12c. The cooling water jacket 12c is formed on the peripheral wall 12b of the motor housing 12. The cooling water jacket 12c extends circumferentially throughout the entire peripheral wall 12b.

[0066] like Figure 2 As shown, the first end of the cooling water passage W1 is connected to the cooling water jacket 12c via the cooling water passage W2. Additionally, the second end of the cooling water passage W1 is connected to the cooling water jacket 12c via the cooling water passage W3.

[0067] The first end and the second end of the external flow path to which the cooling jacket 12c is connected are not shown. Cooling water (LLC) flows in the external flow path. In addition, a radiator not shown is provided in the external flow path. The cooling water flowing in the external flow path is cooled by heat exchange with outside air when passing through the radiator. Thus, the cooling water circulates by flowing in the order of the external flow path, the cooling jacket 12c, the connecting cooling water passage W2, the cooling water passage Wl, the connecting cooling water passage W3, and the cooling jacket 12c. Therefore, the cooling water flows in the cooling water passage Wl. The cooling water flowing in the cooling water passage Wl cools the seal plate 17. Thus, the seal plate 17 has, in the inside of the seal plate 17, the cooling gas passage Gl for the cooling gas for cooling the first and second thrust bearings 60 and 61 to flow, and the cooling water passage Wl for the cooling water for cooling the seal plate 17 to flow.

[0068] <Effects>

[0069] Next, the effects of the present embodiment will be described.

[0070] The seal plate 17 has, in the inside of the seal plate 17, the cooling gas passage Gl. The air cools the first and second thrust bearings 60 and 61, and also cools the seal plate 17 by flowing in the cooling gas passage Gl. Also, the seal plate 17 has, in the inside of the seal plate 17, the cooling water passage Wl. The cooling water flowing in the cooling water passage Wl cools the seal plate 17. Therefore, the heat of the air compressed by the compressor impeller 34 is less likely to be transmitted to the first and second thrust bearings 60 and 61 housed in the thrust bearing housing chamber S2 via the seal plate 17. Thus, the first and second thrust bearings 60 and 61 are efficiently cooled by the air. Also, the heat of the first and second thrust bearings 60 and 61 is radiated to the cooling water flowing in the cooling water passage Wl.

[0071] <Effects>

[0072] The following effects can be obtained in the above-described embodiment.

[0073] (1) The seal plate 17 has a cooling gas passage G1 inside the seal plate 17. Therefore, air is able to cool the first and second thrust bearings 60 and 61, and also cool the seal plate 17 by flowing in the cooling gas passage G1. Further, the seal plate 17 has a cooling water passage W1 inside the seal plate 17, so the seal plate 17 is able to be further cooled by cooling water. Therefore, the heat of the air compressed by the compressor impeller 34 is less likely to be transmitted to the first and second thrust bearings 60 and 61 housed in the thrust bearing housing chamber S2 via the seal plate 17. Thus, the first and second thrust bearings 60 and 61 are able to be efficiently cooled by air. Further, the heat of the first and second thrust bearings 60 and 61 is dissipated to the cooling water flowing in the cooling water passage W1. Therefore, the cooling performance for the first and second thrust bearings 60 and 61 is able to be improved.

[0074] (2) The cooling water passage W1 is located at a position radially outward of the cooling gas passage G1 with respect to the rotation axis 30. According to this, compared to a case where the cooling water passage W1 is located at a position radially inward of the cooling gas passage G1 with respect to the rotation axis 30, the surface area of the cooling water passage W1 is able to be increased. Therefore, the seal plate 17 is able to be efficiently cooled. As a result, the heat of the fluid compressed by the compressor impeller 34 is less likely to be transmitted to the first and second thrust bearings 60 and 61 housed in the thrust bearing housing chamber S2 via the seal plate 17. Further, the heat of the first and second thrust bearings 60 and 61 is more likely to be dissipated to the cooling water flowing in the cooling water passage W1. As a result, the cooling performance of the first and second thrust bearings 60 and 61 is able to be further improved.

[0075] <Modification Example>

[0076] Further, the above-described embodiment can be implemented as follows. The above-described embodiment and the following modification example can be implemented in combination with each other within a range that does not contradict in technology.

[0077] In the embodiment, the cooling water passage W1 can also be located at a position radially inward of the cooling gas passage G1.

[0078] In the embodiment, the groove 17d can also not be meandering. In general, the shape of the groove 17d is not particularly limited.

[0079] In the embodiment, the cooling water flowing in the cooling water passage W1 can also be cooling water other than the cooling water flowing in the cooling water jacket 12c. In general, the flow method of the cooling water to the cooling water passage W1 is not particularly limited.

[0080] In the embodiment, the air that has cooled the first thrust bearing 60 and the second thrust bearing 61 in the thrust bearing housing chamber S2 is caused to flow into the cooling gas passage G1, but the present application is not limited thereto. For example, the air that has flowed in the cooling gas passage G1 can be caused to flow into the thrust bearing housing chamber S2 to cool the first thrust bearing 60 and the second thrust bearing 61.

[0081] In the embodiment, a part of the air compressed by the compressor impeller 34 is caused to flow into the cooling gas passage G1 as the cooling gas that flows in the cooling gas passage G1, but the present application is not limited thereto. Air other than the air compressed by the compressor impeller 34 can be caused to flow into the cooling gas passage G1.

[0082] In the embodiment, the centrifugal compressor 10 can be configured not to have the turbine working wheel 35.

[0083] In the embodiment, the centrifugal compressor 10 can be configured to have a compressor impeller instead of the turbine working wheel 35. That is, the centrifugal compressor 10 can be configured to have compressor impellers at both ends of the rotary shaft 30, and the fluid compressed by one of the compressor impellers is compressed again by the other compressor impeller.

[0084] In the embodiment, for example, the centrifugal compressor 10 can be an engine-driven centrifugal compressor.

[0085] In the embodiment, the centrifugal compressor 10 can not be mounted on a fuel cell vehicle, and for example, can be used for a vehicle air conditioning device to compress a refrigerant as the fluid. The centrifugal compressor 10 is not limited to be mounted on a vehicle.

[0086] [Explanation of Reference Numerals]

[0087] 10…centrifugal compressor, 11…housing, 13b…impeller chamber, 17…sealing plate as a partition wall, 30…rotary shaft, 34…compressor impeller, 60…first thrust bearing as a thrust bearing, 61…second thrust bearing as a thrust bearing, G1…cooling gas passage, S2…thrust bearing housing chamber, W1…cooling water passage.

Claims

1. A centrifugal compressor, comprising: Rotation axis; A compressor impeller is mounted on the rotating shaft and compresses fluid by rotating integrally with the rotating shaft; Housing, housing the rotating shaft and the compressor impeller; and A thrust bearing supports the rotating shaft in the thrust direction, enabling it to rotate. The housing has: Impeller chamber, which houses the compressor impeller; A thrust bearing housing chamber for housing the thrust bearing; and A partition wall separates the impeller chamber from the thrust bearing housing chamber. The partition wall has, inside its interior: a cooling gas passage for the flow of cooling gas to cool the thrust bearing; and a cooling water passage for the flow of cooling water to cool the partition wall. The cooling gas passage and the cooling water passage are formed on the axial end face of the thrust bearing housing side of the partition wall.

2. The centrifugal compressor according to claim 1, The cooling water passage is located radially outside the rotating axis than the cooling gas passage.

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