Centrifugal compressor

Abstract

To secure reliability of a centrifugal compressor.SOLUTION: Both of a first resin part 60 and each second resin part 70 and both of each second resin part 70 and each conductive member 54 are bonded by an insertion molding, together. Each second resin part 70 has a Young rate smaller than that of the first resin part 60. Even if a force for peeling the first resin part 60 and each conductive member 54 each other occurs due to a difference of a liner expansion coefficient of the first resin part 60 and a liner expansion coefficient of each conductive member 54, an adhesion to each conductive member 54 and the first resin part 60, respectively in each second resin part 70 is secured. Even if both of the first resin part 60 and each conductive member 54 are peeled out each other, each second resin part 70 can be easily elastically deformed by tracking to each conductive member 54 and the first resin part 60. Thus, the adhesion against each conductive member 54 and the first resin part 60 in each second resin part 70 is maintained. Therefore, by each second resin part 70, a seal performance between the first resin part 60 and each conductive member 54 is secured.SELECTED DRAWING: Figure 2

Description

Technical Field

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

Background Art

[0002] For example, as disclosed in Patent Document 1, a centrifugal compressor including a compressor impeller, a motor, an inverter, and a housing has been conventionally known. The compressor impeller compresses a fluid. The motor rotates the compressor impeller. The inverter drives the motor. The housing has a motor chamber and an inverter chamber. The motor chamber houses the motor. The inverter chamber houses the inverter.

[0003] Such a centrifugal compressor includes a conductive member that electrically connects the motor and the inverter. An insertion hole through which the conductive member is inserted is formed in the housing. The insertion hole penetrates the housing. Further, the centrifugal compressor includes a resin member that holds the conductive member. The resin member is fixed to the housing while holding the conductive member. The resin member seals between itself and the conductive member. Then, the motor is driven by power from the inverter being supplied to the motor via the conductive member.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, in such centrifugal compressors, the motor chamber may be operated at a pressure higher than the inverter chamber. In this case, the difference between the coefficient of thermal expansion of the resin component and the conductive component may generate a force that separates the resin component and the conductive component from each other. As a result, there is a risk that air flowing from the motor chamber into the through-hole may pass between the resin component and the conductive component and enter the inverter chamber. If air enters the inverter chamber, it may cool down and cause condensation inside the inverter chamber. If condensation occurs inside the inverter chamber, it may adversely affect the inverter, potentially reducing the reliability of the centrifugal compressor. [Means for solving the problem]

[0006] A centrifugal compressor that solves the above problems comprises a compressor impeller for compressing a fluid, a motor for rotating the compressor impeller, an inverter for driving the motor, a housing having a motor chamber for housing the motor and an inverter chamber for housing the inverter, a conductive member for electrically connecting the motor and the inverter, a through hole that penetrates the housing and through which the conductive member is inserted, and a resin member fixed to the housing while holding the conductive member and sealing the space between the conductive member and the resin member, wherein the pressure in the motor chamber is higher than the pressure in the inverter chamber, and the resin member comprises a first resin part fixed to the housing, and a second resin part that is covered by the first resin part and covers the conductive member, and has a Young's modulus smaller than that of the first resin part, and the space between the first resin part and the second resin part, and the space between the second resin part and the conductive member are both joined by insert molding.

[0007] According to this, for example, even if a force is generated that separates the first resin part and the conductive member due to the difference in the coefficient of thermal expansion between the first resin part and the conductive member, the adhesion between the second resin part and the conductive member and the first resin part is ensured. Furthermore, since the second resin part has a smaller Young's modulus than the first resin part, even if the first resin part and the conductive member are separated, the second resin part is more likely to elastically deform in accordance with the conductive member and the first resin part. Therefore, the adhesion between the conductive member and the first resin part and the second resin part is maintained. Consequently, the second resin part ensures a seal between the first resin part and the conductive member, thus preventing air flowing from the motor chamber into the insertion hole from passing between the first resin part and the conductive member and entering the inverter chamber. As a result, it is possible to avoid problems such as condensation occurring in the inverter chamber due to the cooling of air that has entered the inverter chamber, which would adversely affect the inverter. In this way, the reliability of the centrifugal compressor can be ensured.

[0008] In the centrifugal compressor described above, the first resin part is preferably fixed to the housing while positioned inside the inverter chamber. According to this, the first resin part is not exposed to the high-pressure air inside the motor chamber, thus improving the durability of the first resin part. Therefore, it becomes easier to ensure the reliability of the centrifugal compressor.

[0009] In the centrifugal compressor described above, the conductive member is plate-shaped, and a through hole is formed in the conductive member that penetrates in the thickness direction of the conductive member, and the second resin part has an anchor part that engages with the through hole.

[0010] According to this, the anchor portion is locked into the through hole, allowing the second resin portion to be precisely positioned relative to the conductive member. Therefore, the second resin portion makes it easier to further ensure a seal between the first resin portion and the conductive member. [Effects of the Invention]

[0011] According to this invention, the reliability of centrifugal compressors can be ensured. [Brief explanation of the drawing]

[0012] [Figure 1] This is a cross-sectional view of a centrifugal compressor in an embodiment. [Figure 2] This is a cross-sectional view showing a magnified portion of a centrifugal compressor. [Figure 3] This is a cross-sectional view showing the relationship between the conductive member, the first resin part, and the second resin part. [Figure 4] This is a cross-sectional view showing an enlarged portion of a centrifugal compressor in another embodiment. [Figure 5] This is a cross-sectional view showing the relationship between the conductive member, the first resin part, and the second resin part. [Modes for carrying out the invention]

[0013] Below, one embodiment of the centrifugal compressor will be described with reference to Figures 1 to 3. The centrifugal compressor of this embodiment is installed in a fuel cell vehicle. The centrifugal compressor constitutes part of the fuel cell system installed in the fuel cell vehicle.

[0014] <Fuel cell system 1> As shown in Figure 1, the fuel cell system 1 comprises a fuel cell stack 2 and a centrifugal compressor 10. The centrifugal compressor 10 supplies air as a fluid to the fuel cell stack 2. The fuel cell stack 2 is composed of a plurality of battery cells (not shown). Each battery cell is composed of an oxygen electrode, a hydrogen electrode, and an electrolyte membrane placed between the two electrodes, stacked in a single layer. The fuel cell stack 2 generates electricity by chemically reacting hydrogen, which is the fuel gas, with oxygen in the air. The fuel cell stack 2 is electrically connected to a traction motor (not shown). The traction motor is driven using the electricity generated by the fuel cell stack 2 as its power source. The power of the traction motor is transmitted to the axle via a power transmission mechanism (not shown). As a result, the vehicle travels at a speed corresponding to the accelerator pedal opening.

[0015] The fuel cell system 1 includes a supply pipe L1, a discharge pipe L2, and a branch pipe L3. The supply pipe L1 is connected to the supply port 2a of the fuel cell stack 2. The supply pipe L1 supplies air to the fuel cell stack 2. The discharge pipe L2 is connected to the discharge port 2b of the fuel cell stack 2. The air from the fuel cell stack 2 is discharged into the discharge pipe L2.

[0016] The branch pipe L3 branches from the supply pipe L1. A part of the air flowing in the supply pipe L1 branches and flows in the branch pipe L3. An intercooler R1 is provided in the middle of the branch pipe L3. The intercooler R1 is configured to be able to cool the air flowing in the branch pipe L3.

[0017] <Centrifugal compressor 10> The centrifugal compressor 10 includes a housing 11. The housing 11 is made of a metal material, for example, made of aluminum. The housing 11 has a motor housing 12, a compressor housing 13, a turbine housing 14, a first plate 15, a second plate 16, and a seal plate 17.

[0018] The motor housing 12 is cylindrical. The motor housing 12 has a plate-shaped end wall 12a and a peripheral wall 12b. The peripheral wall 12b extends cylindrically from the outer peripheral portion of the end wall 12a. The first plate 15 is connected to the 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. And the end wall 12a and the peripheral wall 12b of the motor housing 12 and the first plate 15 define a motor chamber S1. Therefore, the housing 11 has a motor chamber S1.

[0019] On the end face 15a of the first plate 15 opposite to the motor housing 12, a first recess 15c and a second recess 15d are formed. The first recess 15c and the second recess 15d are circular holes. The inner diameter of the first recess 15c is larger than the inner diameter of the second recess 15d. The axis of the first recess 15c coincides with the axis of the second recess 15d. The inner peripheral surface of the first recess 15c connects the end face 15a and the bottom surface of the first recess 15c. The inner peripheral surface of the second recess 15d connects the bottom surface of the first recess 15c and the bottom surface of the second recess 15d.

[0020] 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 projects into the motor chamber S1 from the central portion of the end face 15b on the motor housing 12 side of the first plate 15. The first bearing holding portion 20 penetrates the first plate 15 and opens to the bottom surface of the second recess 15d. The axis of the first bearing holding portion 20 coincides with the axis of the first recess 15c and the second recess 15d.

[0021] The motor housing 12 has a second bearing holding portion 21. The second bearing holding portion 21 is cylindrical. The second bearing holding portion 21 projects into the motor chamber S1 from the central portion of the inner surface of the end wall 12a of the motor housing 12. The inside of the second bearing holding portion 21 penetrates the end wall 12a of the motor housing 12 and opens to the outer surface of the end wall 12a. The axis of the first bearing holding portion 20 coincides with the axis of the second bearing holding portion 21.

[0022] The second plate 16 is connected to the outer surface of the end wall 12a of the motor housing 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 inside 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. A shaft insertion hole 17a is formed in the central portion of the seal plate 17. The axis of the shaft insertion hole 17a coincides with the axis of the first bearing holding portion 20.

[0023] The seal plate 17 is attached to the first plate 15 with the seal plate 17 fitted into the first recess 15c. The seal plate 17 closes the opening of the second recess 15d. The thrust bearing housing chamber S2 is partitioned by the seal plate 17 and the second recess 15d of the first plate 15.

[0024] The compressor housing 13 is cylindrical. The compressor housing 13 has a circular inlet 13a. The compressor housing 13 is connected to the end face 15a of the first plate 15 such that the axis of the inlet 13a coincides with the axis of the shaft insertion hole 17a of the seal plate 17 and the axis of the first bearing holding portion 20. The inlet 13a opens on the end face of the compressor housing 13 opposite to the first plate 15.

[0025] Between the compressor housing 13 and the seal plate 17, there is an impeller chamber 13b, a discharge chamber 13c, and a diffuser passage 13d. The impeller chamber 13b communicates with the intake port 13a. The discharge chamber 13c extends around the axis of the intake port 13a, surrounding the impeller chamber 13b. The supply pipe L1 is connected to the discharge chamber 13c. The diffuser passage 13d connects the impeller chamber 13b and the discharge chamber 13c. The impeller chamber 13b communicates with the shaft insertion hole 17a of the seal plate 17.

[0026] The turbine housing 14 is cylindrical. The turbine housing 14 has a circular discharge port 14a. The turbine housing 14 is connected to the end face 16b of the second plate 16 opposite to the motor housing 12, such that the axis of the discharge port 14a coincides with the axis of the shaft insertion hole 16a of the second plate 16 and the axis of the second bearing holding portion 21. The discharge port 14a opens to the end face of the turbine housing 14 opposite to the second plate 16.

[0027] Between the turbine housing 14 and the end face 16b of the second plate 16, a turbine chamber 14b, a turbine scroll flow path 14c, and a communication flow path 14d are formed. Therefore, the housing 11 has a turbine chamber 14b. The turbine chamber 14b communicates with the discharge port 14a. The turbine scroll flow path 14c extends around the turbine chamber 14b and around the axis of the discharge port 14a. The discharge pipe L2 is connected to the turbine scroll flow path 14c. The communication flow path 14d connects the turbine chamber 14b and the turbine scroll flow path 14c. The turbine chamber 14b communicates with the shaft insertion hole 16a.

[0028] The centrifugal compressor 10 includes a rotating body 29. The rotating body 29 has a rotating shaft 30, a first support portion 31, a second support portion 32, and a support plate 33. The rotating shaft 30, the first support portion 31, the second support portion 32, and the support plate 33 are housed within the housing 11.

[0029] The rotating shaft 30 is housed within the housing 11 with its axial direction aligned with the axial direction of the motor housing 12. The first end 30a of the rotating shaft 30 protrudes into the impeller chamber 13b, passing through the motor chamber S1, the inside of the first bearing holder 20, the thrust bearing housing chamber S2, and the shaft insertion hole 17a. The second end 30b of the rotating shaft 30 protrudes into the turbine chamber 14b, passing through the motor chamber S1, the inside of the second bearing holder 21, and the shaft insertion hole 16a.

[0030] A first sealing member 22 is provided between the shaft insertion hole 17a of the seal plate 17 and the rotating shaft 30. The first sealing member 22 suppresses air leakage from the impeller chamber 13b toward the motor chamber S1. A second sealing member 23 is provided between the shaft insertion hole 16a of the second plate 16 and the rotating shaft 30. The second sealing member 23 suppresses air leakage from the turbine chamber 14b toward the motor chamber S1. The first sealing member 22 and the second sealing member 23 are, for example, sealing rings.

[0031] The first support portion 31 is provided on the outer circumferential surface of the rotating shaft 30, near the first end portion 30a. The first support portion 31 is located inside the first bearing retaining portion 20. The first support portion 31 is integrally formed with the rotating shaft 30. The first support portion 31 protrudes from the outer circumferential surface of the rotating shaft 30.

[0032] The second support portion 32 is provided on the outer circumferential surface of the rotating shaft 30, near the second end portion 30b. The second support portion 32 is positioned inside the second bearing retaining portion 21. The second support portion 32 is fixed to the outer circumferential surface of the rotating shaft 30, protruding annularly from the outer circumferential surface of the rotating shaft 30. The second support portion 32 is rotatable integrally with the rotating shaft 30.

[0033] The support plate 33 is housed in the thrust bearing housing chamber S2. The support plate 33 is fixed to the outer surface of the rotating shaft 30, protruding annularly radially outward from the outer surface of the rotating shaft 30. Therefore, the support plate 33 is separate from the rotating shaft 30. The support plate 33 is rotatable integrally with the rotating shaft 30.

[0034] The centrifugal compressor 10 is equipped with a compressor impeller 34. The compressor impeller 34 is mounted on the first axial end 30a of the rotating shaft 30. The compressor impeller 34 is positioned closer to the first end 30a than the support plate 33 on the rotating shaft 30. The compressor impeller 34 is housed in the impeller chamber 13b. The compressor impeller 34 rotates integrally with the rotating shaft 30.

[0035] The compressor impeller 34 compresses the air drawn in from the intake port 13a within the impeller chamber 13b. Thus, the compressor impeller 34 compresses the air as a fluid. The air compressed by the compressor impeller 34 then passes through the diffuser flow path 13d and is discharged into the discharge chamber 13c. The air discharged into the discharge chamber 13c is then discharged into the supply pipe L1. The air flowing through the supply pipe L1 is supplied to the fuel cell stack 2.

[0036] The centrifugal compressor 10 is equipped with a turbine wheel 35. The turbine wheel 35 is attached to the second end 30b of the rotating shaft 30. The turbine wheel 35 is positioned closer to the second end 30b than the second support portion 32 on the rotating shaft 30. The turbine wheel 35 is housed in the turbine chamber 14b. The turbine wheel 35 rotates integrally with the rotating shaft 30. The turbine wheel 35 is rotated by air flowing from the fuel cell stack 2 into the turbine chamber 14b via the discharge pipe L2, the turbine scroll passage 14c, and the communication passage 14d.

[0037] The centrifugal compressor 10 is equipped with a first radial bearing 25 and a second radial bearing 26. The first radial bearing 25 is cylindrical. The first radial bearing 25 is held in a first bearing holder 20. The second radial bearing 26 is cylindrical. The second radial bearing 26 is held in a second bearing holder 21. The first radial bearing 25 and the second radial bearing 26 support the rotating shaft 30 so that it can rotate relative to the housing 11 in the radial direction. The "radial direction" refers to the direction perpendicular to the axial direction of the rotating shaft 30.

[0038] The centrifugal compressor 10 is equipped with a first thrust bearing 27 and a second thrust bearing 28. The first thrust bearing 27 and the second thrust bearing 28 rotatably support the support plate 33 in the thrust direction relative to the housing 11. The "thrust direction" is the direction parallel to the axial direction of the rotation shaft 30.

[0039] The first thrust bearing 27 and the second thrust bearing 28 are housed in the thrust bearing housing chamber S2. The first thrust bearing 27 and the second thrust bearing 28 are positioned so as to sandwich the support plate 33. The first thrust bearing 27 is positioned on the side of the support plate 33 that faces the compressor impeller 34. The second thrust bearing 28 is positioned on the side of the support plate 33 that faces the compressor impeller 34.

[0040] <Motor 40> The centrifugal compressor 10 is equipped with a motor 40. The motor 40 is housed in a motor chamber S1. Therefore, the motor chamber S1 houses the motor 40. The motor 40 is equipped with a cylindrical rotor 41 and a cylindrical stator 42. The rotor 41 is fixed to the rotating shaft 30. The stator 42 is fixed to the housing 11. The rotor 41 is positioned radially inward of the stator 42 and rotates integrally with the rotating shaft 30. The rotor 41 has a cylindrical rotor core 41a fixed to the rotating shaft 30 and a plurality of permanent magnets (not shown) provided on the rotor core 41a. The stator 42 surrounds the rotor 41.

[0041] The stator 42 has a cylindrical stator core 43 fixed to the inner circumferential surface of the peripheral wall 12b of the motor housing 12, and a coil 44 wound around the stator core 43. The coil 44 has coil ends 44e protruding from both end faces of the stator core 43. The rotating shaft 30 rotates integrally with the rotor 41 when current flows from a battery (not shown) to the coil 44. The motor 40 rotates the compressor impeller 34 by rotating the rotating shaft 30. The motor 40 is positioned between the compressor impeller 34 and the turbine wheel 35 in the axial direction of the rotating shaft 30.

[0042] <Introduction channel 46> The centrifugal compressor 10 is equipped with an introduction channel 46. The introduction channel 46 is formed in the first plate 15. The introduction channel 46 extends radially with respect to the rotating shaft 30. The first end of the introduction channel 46 opens to the outer surface of the first plate 15. The first end of the introduction channel 46 is connected to the branch pipe L3. The second end of the introduction channel 46 communicates with the thrust bearing housing chamber S2.

[0043] A portion of the air that is compressed by the compressor impeller 34 and flows through the supply pipe L1 toward the fuel cell stack 2 enters the intake channel 46 via the branch pipe L3. The air entering the intake channel 46 is cooled by the intercooler R1 as it flows through the branch pipe L3. The air that enters the intake channel 46 flows into the thrust bearing housing chamber S2. The air in the thrust bearing housing chamber S2 passes inside the first bearing holder 20. The air that has passed inside the first bearing holder 20 is then introduced into the motor chamber S1. Therefore, the intake channel 46 introduces a portion of the air compressed by the compressor impeller 34 into the motor chamber S1.

[0044] <Discharge channel 47> The centrifugal compressor 10 is equipped with a discharge channel 47. The discharge channel 47 is formed in the second plate 16. The discharge channel 47 extends radially with respect to the rotating shaft 30. The first end of the discharge channel 47 opens onto the outer surface of the second plate 16. The first end of the discharge channel 47 communicates with the outside. The second end of the discharge channel 47 communicates with a portion of the shaft insertion hole 16a that is closer to the motor housing 12 than the second seal member 23. The air inside the motor chamber S1 is then discharged to the outside through the discharge channel 47 after passing inside the second bearing holder 21 and through the shaft insertion hole 16a.

[0045] <Inverter 50> The housing 11 has an inverter case 51. The inverter case 51 has a case body 52 and a cover 53. The case body 52 has a plate-shaped case end wall 52a and a case peripheral wall 52b. The case peripheral wall 52b extends cylindrically from the outer circumference of the case end wall 52a. The cover 53 is plate-shaped. The cover 53 is connected to the case body 52 with the opening of the case peripheral wall 52b closed. The inverter room S3 is partitioned by the case end wall 52a and case peripheral wall 52b of the case body 52 and the cover 53. Therefore, the housing 11 has an inverter room S3.

[0046] The inverter case 51 is fixed to the motor housing 12 with the outer surface of the case end wall 52a in contact with the outer surface of the peripheral wall 12b of the motor housing 12. Therefore, the inverter chamber S3 is located radially outward from the motor chamber S1 relative to the rotation shaft 30.

[0047] The centrifugal compressor 10 is equipped with an inverter 50. The inverter 50 is housed in an inverter chamber S3. Therefore, the inverter chamber S3 houses the inverter 50. The inverter 50 is located radially outward from the rotation axis 30 relative to the motor 40. The inverter 50 drives the motor 40.

[0048] <Conductive member 54> The centrifugal compressor 10 has conductive members 54. The centrifugal compressor 10 has three conductive members 54. Figure 1 shows one of the three conductive members 54. Each conductive member 54 is a plate-shaped busbar. The first end of each conductive member 54 is electrically connected to three motor wires 45 that are drawn out from the coil ends 44e of the coil 44. Each motor wire 45 is drawn out from the coil end 44e located on the compressor impeller 34 side of the coil ends 44e that protrude from both ends of the stator core 43. The three motor wires 45 correspond to the U phase, V phase, and W phase of the coil 44, respectively. Each conductive member 54 is electrically connected to each motor wire 45 in a manner corresponding to the U phase, V phase, and W phase of the coil 44, respectively. The second end of each conductive member 54 is electrically connected to the inverter 50. Therefore, each conductive member 54 electrically connects the motor 40 and the inverter 50.

[0049] <Through hole 55> A first through-hole 56 is formed in the peripheral wall 12b of the motor housing 12. The first through-hole 56 is formed in the peripheral wall 12b of the motor housing 12, near the first plate 15. The first through-hole 56 penetrates the peripheral wall 12b. The first through-hole 56 opens to the area between the stator core 43 and the first plate 15 on the inner surface of the peripheral wall 12b. The first through-hole 56 communicates with the motor chamber S1. Specifically, the first through-hole 56 communicates with the area between the stator core 43 and the first plate 15 in the motor chamber S1.

[0050] A second through-hole 57 is formed in the case end wall 52a. The second through-hole 57 penetrates the case end wall 52a. The first end of the second through-hole 57 communicates with the first through-hole 56. The second end of the second through-hole 57 communicates with the inverter chamber S3. Each conductive member 54 passes through the first through-hole 56 and the second through-hole 57. Therefore, the first through-hole 56 and the second through-hole 57 penetrate the housing 11 and form an insertion hole 55 through which each conductive member 54 is inserted. Thus, the centrifugal compressor 10 is equipped with an insertion hole 55.

[0051] <Resin component 59> As shown in Figures 2 and 3, the centrifugal compressor 10 is equipped with a resin member 59. The resin member 59 is fixed to the housing 11 while holding each conductive member 54 and seals the space between the conductive member 54 and the resin member 59. The resin member 59 comprises a first resin part 60 and a second resin part 70.

[0052] <First resin part 60> The first resin part 60 is a synthetic resin. The first resin part 60 is a thermoplastic resin. The first resin part 60 is formed of, for example, polyphenylene sulfide resin (PPS). The first resin part 60 has a holding part 61 and a fixing part 62.

[0053] The holding portion 61 covers a part of each conductive member 54. Specifically, the holding portion 61 has three holding holes 63. In Figure 2, one of the three holding holes 63 is shown. Each conductive member 54 passes through each holding hole 63. The inner circumferential surface of each holding hole 63 is in close contact with the outer surface of each conductive member 54. The holding portion 61 holds each conductive member 54 that passes through each holding hole 63. Therefore, the first resin portion 60 holds each conductive member 54. The first resin portion 60 ensures insulation between adjacent conductive members 54. The holding portion 61 also has a first contact surface 61a. The first contact surface 61a is flat. Each holding hole 63 opens onto the first contact surface 61a.

[0054] The first resin part 60 has two fixing parts 62. Each fixing part 62 is plate-shaped. Each fixing part 62 protrudes from the outer surface of the holding part 61. Each fixing part 62 has a second contact surface 62a that is continuous with the first contact surface 61a of the holding part 61. A bolt insertion hole 62h is formed in each fixing part 62. The bolt insertion hole 62h penetrates the fixing part 62 in the thickness direction. A bolt 64 can be inserted through the bolt insertion hole 62h. With the first contact surface 61a of the holding part 61 and the second contact surface 62a of each fixing part 62 in contact with the inner surface of the case end wall 52a, each bolt 64 inserted through each bolt insertion hole 62h is screwed into the case end wall 52a. As a result, the first resin part 60 is fixed to the case end wall 52a. Therefore, the first resin part 60 is fixed to the housing 11 while holding each conductive member 54. Therefore, the first resin part 60 is fixed to the housing 11 while positioned inside the inverter chamber S3.

[0055] <Gasket 65> The centrifugal compressor 10 is equipped with a gasket 65. The gasket 65 is annular in shape. The gasket 65 is made of, for example, rubber. The gasket 65 is positioned on the outer circumference of the first contact surface 61a. The gasket 65 extends along the outer circumference of the first contact surface 61a. The gasket 65 is attached to the first contact surface 61a so as to surround the three retaining holes 63. The gasket 65 seals the space between the first resin part 60 and the case end wall 52a. The gasket 65 prevents air flowing from the motor chamber S1 into the through hole 55 from entering the inverter chamber S3 through the space between the first resin part 60 and the case end wall 52a.

[0056] <Second resin part 70> The resin member 59 comprises three second resin parts 70. Each second resin part 70 is made of thermoplastic polyester elastomer. The second resin part 70 is Hytrel (registered trademark). Therefore, each second resin part 70 is made of a material with rubber elasticity. The second resin part 70 has a smaller Young's modulus than the first resin part 60.

[0057] Each second resin part 70 is annular. Each second resin part 70 covers a portion of each conductive member 54. Each second resin part 70 covers each conductive member 54. Each second resin part 70 is provided between each retaining hole 63 and each conductive member 54. The inner circumferential surface of each second resin part 70 is in close contact with the outer surface of each conductive member 54. The outer circumferential surface of each second resin part 70 is in close contact with the inner circumferential surface of each retaining hole 63. Each second resin part 70 seals the space between each conductive member 54 and each retaining hole 63. Therefore, each second resin part 70 seals the space between the first resin part 60 and each conductive member 54. Each second resin part 70 is covered by the first resin part 60.

[0058] Each second resin part 70 has a greater adhesion force to each conductive member 54 and the first resin part 60 than the force that separates the first resin part 60 and each conductive member 54, which is caused by the difference between the coefficient of thermal expansion of the first resin part 60 and the coefficient of thermal expansion of each conductive member 54. The second resin part 70 has a smaller Young's modulus than the first resin part 60.

[0059] The first resin part 60 and each second resin part 70 are integrated with each conductive member 54 by insert molding with each conductive member 54. Specifically, first, a primary molding process is performed in which each second resin part 70 is insert molded into each conductive member 54. This integrates each second resin part 70 with each conductive member 54. Subsequently, a secondary molding process is performed in which the first resin part 60 is insert molded into each conductive member 54 into which each second resin part 70 has been integrated. This integrates each first resin part 60 with each conductive member 54. In this way, the first resin part 60 and each second resin part 70, and the second resin part 70 and each conductive member 54 are joined by insert molding.

[0060] [Effect of the Embodiment] Next, the operation of this embodiment will be described. A portion of the air compressed by the compressor impeller 34 flows into the thrust bearing housing chamber S2 via the introduction channel 46. The first thrust bearing 27 and the second thrust bearing 28 are cooled by the air that flows into the thrust bearing housing chamber S2 from the introduction channel 46. The air in the thrust bearing housing chamber S2 flows into the inside of the first bearing holder 20. The first radial bearing 25 is cooled by the air that passes through the inside of the first bearing holder 20.

[0061] Air passing inside the first bearing holder 20 is introduced into the motor chamber S1. The motor 40 is cooled by the air introduced into the motor chamber S1. The air inside the motor chamber S1 flows into the second bearing holder 21. The second radial bearing 26 is cooled by the air passing inside the second bearing holder 21. The air passing inside the second bearing holder 21 passes through the shaft insertion hole 16a and is discharged to the outside through the discharge passage 47. In this way, the first thrust bearing 27, the second thrust bearing 28, the first radial bearing 25, the motor 40, and the second radial bearing 26 are cooled by a portion of the air compressed by the compressor impeller 34.

[0062] The air passing through the fuel cell stack 2 is discharged to the exhaust pipe L2 as exhaust from the fuel cell stack 2. The air from the fuel cell stack 2 is discharged to the turbine chamber 14b through the exhaust pipe L2, the turbine scroll passage 14c, and the communication passage 14d. The turbine wheel 35 rotates due to the air discharged to the turbine chamber 14b. The rotating shaft 30 rotates not only due to the drive of the motor 40, but also due to the rotation of the turbine wheel 35, which rotates due to the air discharged to the turbine chamber 14b. The rotation of the rotating shaft 30 is assisted by the rotation of the turbine wheel 35 due to the air discharged to the turbine chamber 14b. The air that has passed through the turbine chamber 14b is discharged to the outside from the discharge port 14a.

[0063] Incidentally, since some of the air compressed by the compressor impeller 34 is introduced into the motor chamber S1, the pressure inside the motor chamber S1 is higher than the pressure inside the inverter chamber S3. In addition, air from the impeller chamber 13b may also flow into the motor chamber S1 by passing through the shaft insertion hole 17a, the thrust bearing housing chamber S2, and the inside of the first bearing retaining part 20. In this case as well, the pressure inside the motor chamber S1 is higher than the pressure inside the inverter chamber S3.

[0064] Thus, in the centrifugal compressor 10, the motor may be operated with a pressure higher than the pressure in the inverter chamber S3. At this time, the difference between the coefficient of thermal expansion of the first resin part 60 and the coefficient of thermal expansion of each conductive member 54 may generate a force that separates the first resin part 60 and each conductive member 54 from each other. As a result, air flowing from the motor chamber S1 into the insertion hole 55 attempts to enter the inverter chamber S3 by passing through the gap between the first resin part 60 and each conductive member 54.

[0065] In this configuration, the first resin part 60 and each second resin part 70, and the second resin part 70 and each conductive member 54 are joined by insert molding. Each second resin part 70 has a greater adhesion force to each conductive member 54 and the first resin part 60 than the force that separates the first resin part 60 and each conductive member 54 caused by the difference between the coefficient of thermal expansion of the first resin part 60 and the coefficient of thermal expansion of each conductive member 54. Therefore, even if a force separates the first resin part 60 and each conductive member 54 due to the difference between the coefficient of thermal expansion of the first resin part 60 and the coefficient of thermal expansion of each conductive member 54, adhesion between each second resin part 70 and each conductive member 54 and the first resin part 60 is ensured.

[0066] Furthermore, since each second resin part 70 has a smaller Young's modulus than the first resin part 60, even if the first resin part 60 and each conductive member 54 are separated from each other, each second resin part 70 can easily elastically deform to follow the conductive member 54 and the first resin part 60. Therefore, the adhesion between each second resin part 70 and each conductive member 54 and the first resin part 60 is maintained. Consequently, the sealing between the first resin part 60 and each conductive member 54 is ensured by each second resin part 70. This prevents air flowing from the motor chamber S1 into the insertion hole 55 from passing between the first resin part 60 and each conductive member 54 and entering the inverter chamber S3.

[0067] [Effects of the Embodiment] The above embodiment can be achieved to obtain the following effects. (1) The first resin part 60 and each second resin part 70, and the second resin part 70 and each conductive member 54 are joined by insert molding. As a result, even if a force is generated that separates the first resin part 60 and the conductive member 54 due to the difference between the coefficient of thermal expansion of the first resin part 60 and the coefficient of thermal expansion of the conductive member 54, the adhesion of the second resin part 70 to the conductive member 54 and the first resin part 60 is ensured. Furthermore, since the Young's modulus of the second resin part 70 is smaller than that of the first resin part 60, even if the first resin part 60 and the conductive member 54 are separated from each other, the second resin part 70 is more likely to elastically deform in accordance with the conductive member 54 and the first resin part 60. Therefore, the adhesion of the second resin part 70 to the conductive member 54 and the first resin part 60 is maintained. Consequently, the second resin part 70 can ensure a sealing effect between the first resin part 60 and the conductive member 54. Therefore, it is possible to prevent air flowing from the motor chamber S1 into the insertion hole 55 from passing between the first resin part 60 and the conductive member 54 and entering the inverter chamber S3. As a result, it is possible to avoid problems such as condensation occurring in the inverter chamber S3 due to the cooling of air that has entered the inverter chamber S3, which would adversely affect the inverter 50. In this way, the reliability of the centrifugal compressor 10 can be ensured.

[0068] (2) The first resin part 60 is fixed to the housing 11 while positioned inside the inverter chamber S3. This prevents the first resin part 60 from being exposed to the high-pressure air inside the motor chamber S1, thereby improving the durability of the first resin part 60. Therefore, it is easier to ensure the reliability of the centrifugal compressor 10.

[0069] (3) The first resin part 60 is fixed to the case end wall 52a of the inverter case 51 by bolts 64 while it is positioned inside the inverter chamber S3. Therefore, an assembly can be formed in which the resin member 59 that holds the conductive member 54 and the inverter case 51 are integrated. Furthermore, since the inverter case 51 can be assembled to the motor housing 12 with the resin member 59 that holds the conductive member 54 fixed to the inverter case 51, assembly workability can be improved.

[0070] [Differentiation] The above embodiment can be implemented with the following modifications. The above embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0071] ○ As shown in Figures 4 and 5, each conductive member 54 has a through hole 54h that penetrates in the thickness direction of the conductive member 54, and each second resin part 70 may have an anchor part 71 that engages with each through hole 54h. Each second resin part 70 has a seal body part 70a and an anchor part 71. The seal body part 70a is annular in shape that surrounds the conductive member 54. The anchor part 71 is columnar in shape and positioned inside the through hole 54h. The anchor part 71 is integrally formed with the seal body part 70a. The outer circumferential surface of the anchor part 71 is in close contact with the inner circumferential surface of the through hole 54h.

[0072] According to this, the anchor portion 71 is locked into the through hole 54h, allowing the second resin portion 70 to be precisely positioned relative to the conductive member 54. Therefore, the second resin portion 70 makes it easier to further ensure a seal between the first resin portion 60 and the conductive member 54. In addition, when insert molding the second resin portion 70 into the conductive member 54, it is possible to suppress misalignment between the second resin portion 70 and the conductive member 54 due to injection pressure.

[0073] ○ In the embodiment, for example, a notch may be formed on the side of each conductive member 54, and the second resin portion 70 may have an anchor portion that engages with the notch. Even in this case, the second resin portion 70 can be accurately positioned relative to the conductive member 54, as shown in the embodiments of Figures 4 and 5.

[0074] ○ In this embodiment, the first resin portion 60 may be formed of, for example, polybutylene terephthalate resin (PBT) or polycarbonate resin (PC).

[0075] ○ In this embodiment, the resin member 59 had three second resin parts 70, but it is not limited to this, and for example, it may have a configuration in which it has one second resin part that surrounds the three conductive members 54 together.

[0076] ○ In this embodiment, the first resin part 60 may be fixed to the housing 11 while positioned within the motor chamber S1. For example, the first resin part 60 may be fixed to the inner circumferential surface of the peripheral wall 12b of the motor housing 12.

[0077] ○ In this embodiment, for example, a cooling fluid other than the air compressed by the compressor impeller 34 may be introduced into the motor chamber S1. ○ In this embodiment, the centrifugal compressor 10 may be configured without a turbine wheel 35.

[0078] ○ In this embodiment, the centrifugal compressor 10 may be configured to have a compressor impeller instead of a turbine wheel 35. That is, compressor impellers may be attached to both ends of the rotating shaft 30, and the fluid compressed by one compressor impeller may be compressed again by the other compressor impeller.

[0079] ○ In this embodiment, the fuel cell system 1 may be installed in a vehicle other than a fuel cell vehicle. Therefore, the centrifugal compressor 10 is not limited to being installed in a fuel cell vehicle, and the application of the centrifugal compressor 10 may be changed as appropriate.

[0080] ○ In this embodiment, the centrifugal compressor 10 may be used, for example, in a vehicle air conditioning system. Therefore, the fluid compressed by the compressor impeller 34 is not limited to air, but may be, for example, a refrigerant. [Explanation of Symbols]

[0081] 10...Centrifugal compressor, 11...Housing, 34...Compressor impeller, 40...Motor, 50...Inverter, 54...Conductive member, 54h...Through hole, 55...Insertion hole, 59...Resin member, 60...First resin part, 70...Second resin part, 71...Anchor part, S1...Motor room, S3...Inverter room.

Claims

1. A compressor impeller that compresses the fluid, A motor that rotates the compressor impeller, An inverter that drives the motor, A housing having a motor room for housing the motor and an inverter room for housing the inverter, A conductive member that electrically connects the motor and the inverter, The housing has an insertion hole through which the conductive member is inserted, The housing is fixed to the conductive member while holding it, and includes a resin member that seals the space between the conductive member and the housing, The motor chamber is a centrifugal compressor in which the fluid compressed by the compressor impeller is introduced, and the pressure inside the motor chamber is higher than the pressure inside the inverter chamber. The aforementioned resin member is A first resin part, which is fixed to the housing while positioned inside the inverter chamber, The device comprises a second resin portion having a smaller Young's modulus than the first resin portion, which is covered by the first resin portion and surrounds a part of the conductive member, The first resin part covers the second resin part so as to surround the entire second resin part, and the entire first resin part is located inside the inverter chamber. The second resin portion seals the space between the first resin portion and the conductive member. A centrifugal compressor characterized in that the first resin part and the second resin part, and the second resin part and the conductive member are both joined by insert molding.

2. The conductive member is plate-shaped, The conductive member has through holes formed in the thickness direction of the conductive member. The centrifugal compressor according to claim 1, characterized in that the second resin part has an anchor part that is locked into the through hole.

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