centrifugal compressor

Abstract

To electrically connect a motor and an inverter without increasing the number of parts or deteriorating mountability while avoiding an increase in the size of the entire centrifugal compressor. A through-hole 64 is formed in the housing 15, passing through the motor housing member 21, the impeller housing member 22, and the suction housing member 23 in the axial direction of the rotating shaft 11 and communicating with the inside of the inverter housing member 24. A wiring portion 65 is provided in the housing 15 and inserted into the through-hole 64. The through-hole 64 is disposed spaced apart from the first volute 19. An suction passage 63 connecting the suction chamber 17 and the outside of the housing 15 is disposed at a position spaced apart from the through-hole 64 in the circumferential direction of the rotating shaft 11.

Description

[Technical Field]

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

[0002] The centrifugal compressor includes a rotating shaft, a compression mechanism, a motor, an inverter, and a housing. The compression mechanism compresses a fluid as the rotating shaft rotates. The motor rotates the rotating shaft. The inverter drives the motor. The housing accommodates the motor, compression mechanism, and inverter, arranged side by side in this order in the axial direction of the rotating shaft. The compression mechanism includes an impeller, a suction chamber, a diffuser, and a volute. The impeller rotates integrally with the rotating shaft. The diffuser is located downstream of the impeller in the fluid flow direction. The volute communicates with the outlet of the diffuser and is located on the radial outer periphery of the rotating shaft.

[0003] The suction chamber may be located on the inverter side of the impeller in the axial direction of the rotary shaft. In this case, when the suction chamber is located on the inverter side of the impeller in the axial direction of the rotary shaft, heat generated by the inverter is dissipated to the fluid in the suction chamber. As a result, the inverter is efficiently cooled by the fluid in the suction chamber. In addition, the centrifugal compressor includes a wiring section that electrically connects the motor and the inverter. For example, in Patent Document 1, a portion of the wiring section extends outside the housing. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 3-111700 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when the wiring portion extends outside the housing as in Patent Document 1, a seal member is required between the wiring portion and the housing, and the wiring portion needs to be fixed to the housing so that it does not interfere with accessories arranged around the centrifugal compressor. This increases the number of parts and reduces the mountability of the centrifugal compressor. Therefore, it is desired to electrically connect the motor and the inverter without increasing the number of parts or reducing the mountability, while avoiding an increase in the overall size of the centrifugal compressor. [Means for solving the problem]

[0006] A centrifugal compressor that solves the above problem includes a rotating shaft, a compression mechanism that compresses a fluid as the rotating shaft rotates, a motor that rotates the rotating shaft, an inverter that drives the motor, and a housing that accommodates the motor, the compression mechanism, and the inverter, arranged side by side in this order in the axial direction of the rotating shaft, wherein the compression mechanism has an impeller that rotates integrally with the rotating shaft, a suction chamber that is provided on the inverter side of the impeller in the axial direction, a diffuser that is arranged downstream of the impeller in the flow direction of the fluid, and a volute that communicates with an outlet of the diffuser and is provided on the outer periphery of the rotating shaft in the radial direction, and the housing includes a wiring section that electrically connects the motor and the inverter, and the housing includes a motor housing member that accommodates the motor, a suction chamber that is provided on the inverter side of the impeller in the axial direction, a diffuser that is arranged downstream of the impeller in the flow direction of the fluid, and a volute that is provided on the outer periphery of the rotating shaft in the radial direction, and the compressor includes a wiring section that electrically connects the motor and the inverter, and the housing includes a motor housing member that accommodates the motor, a suction chamber that is provided on the inverter side of the impeller in the axial direction, a diffuser that is provided on the The compressor has an impeller housing member that defines a diffuser and the volute, an intake housing member that defines the intake chamber, and an inverter housing member that accommodates the inverter, and the motor housing member, the impeller housing member, the intake housing member, and the inverter housing member are arranged side by side in this order in the axial direction, and a through hole is formed in the housing that passes from the motor housing member through the impeller housing member and the intake housing member in the axial direction and communicates with the inside of the inverter housing member, the wiring portion is provided in the housing and inserted into the through hole, and the through hole is positioned away from the volute, and an intake passage connecting the intake chamber to the outside of the housing is positioned at a position spaced apart from the through hole in the circumferential direction of the rotating shaft.

[0007] According to this, the through-hole passes through the motor housing member, the impeller housing member, and the suction housing member in the axial direction of the rotating shaft and communicates with the inside of the inverter housing member. Furthermore, because the wiring is provided inside the housing and inserted into the through-hole, the wiring can electrically connect the motor and the inverter without extending outside the housing. This eliminates the need for a seal member between the wiring and the housing, which would be necessary if the wiring extended outside the housing. Furthermore, it is no longer necessary to fix the wiring to the housing to prevent it from interfering with accessories arranged around the centrifugal compressor, as would be the case if the wiring extended outside the housing. This avoids an increase in the number of parts and a deterioration in mountability.

[0008] Furthermore, the through hole is disposed away from the volute, and the suction passage is provided at a position spaced apart from the through hole in the circumferential direction of the rotating shaft. Thus, even if the through hole for inserting the wiring is formed to penetrate the impeller housing member and the suction housing member in the axial direction of the rotating shaft, the through hole does not affect the design of the existing volute and suction passage. Therefore, for example, there is no need to change the positions of the volute and the suction passage in order to form the through hole to penetrate the impeller housing member and the suction housing member in the axial direction of the rotating shaft. This avoids the problem of the overall size of the centrifugal compressor increasing due to the positioning of the volute and the suction passage. As described above, the motor and the inverter can be electrically connected without increasing the overall size of the centrifugal compressor, increasing the number of parts, or deteriorating mountability.

[0009] In the centrifugal compressor, the volute preferably has a scroll passage that extends spirally in the circumferential direction around the axis of the rotating shaft, and a discharge passage that branches off from the scroll passage and extends in the circumferential direction around the axis of the rotating shaft radially outward of the scroll passage, and the through hole is preferably arranged on an extension line of the circumferential direction along which the discharge passage extends.

[0010] This makes it possible to avoid an increase in the size of the centrifugal compressor as a whole, compared to when the through-hole is disposed, for example, radially outward of the rotating shaft relative to a circumferential extension of the rotating shaft along which the discharge flow path extends. Therefore, while avoiding an increase in the size of the centrifugal compressor as a whole, the motor and the inverter can be electrically connected without increasing the number of parts or deteriorating mountability.

[0011] In the centrifugal compressor, when viewed from the axial direction, a straight line that passes through the axis of the rotating shaft and passes through a branch point of the discharge flow path from the scroll flow path is defined as a virtual line, and the through hole is preferably located on the same side of the virtual line as the discharge flow path, and is adjacent to the downstream end of the discharge flow path in the circumferential direction.

[0012] In the impeller housing member, when viewed from the axial direction of the rotating shaft, a portion that is located on the same side of the imaginary line as the discharge flow path and adjacent to the downstream end of the discharge flow path in the circumferential direction of the rotating shaft is dead space. Here, the through hole is located on the same side of the imaginary line as the discharge flow path and adjacent to the downstream end of the discharge flow path in the circumferential direction of the rotating shaft. Therefore, the portion that is dead space in the impeller housing member is effectively used as arrangement space for the through hole. Therefore, there is no need to provide a separate arrangement space for the through hole in the impeller housing member, and it is possible to avoid the overall size of the centrifugal compressor being increased due to the provision of the through hole.

[0013] In the centrifugal compressor, the suction chamber may overlap the impeller, the diffuser, and the volute so as to cover them when viewed in the axial direction. This allows the heat of the fluid passing through the diffuser as the impeller rotates and the fluid discharged from the diffuser outlet into the volute to be easily dissipated to the fluid in the suction chamber. Therefore, the heat of the fluid passing through the diffuser as the impeller rotates and the fluid discharged from the diffuser outlet into the volute is less likely to be transferred to the inverter via the housing. As a result, the reliability of the inverter can be improved. Furthermore, the volume of the suction chamber can be maximized, reducing the pulsation of the fluid drawn into the suction chamber.

[0014] In the centrifugal compressor, the wiring section may include a conductive member extending from the inverter into the through hole, motor wiring drawn out from the motor, and a cluster block that houses connection terminals that electrically connect the conductive member and the motor wiring, and the cluster block may be disposed within the through hole.

[0015] This effectively utilizes the through-hole as a space for arranging the cluster block, which is an existing configuration. Therefore, there is no need to provide a separate space for arranging the cluster block, and the overall size of the centrifugal compressor can be reduced. [Effects of the Invention]

[0016] According to the present invention, the motor and the inverter can be electrically connected without increasing the number of parts or deteriorating the mountability, while avoiding an increase in the size of the entire centrifugal compressor. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a cross-sectional view showing a centrifugal compressor according to an embodiment. [Figure 2] FIG. 2 is an enlarged cross-sectional view of a portion of the centrifugal compressor. [Figure 3] FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. [Figure 4]FIG. 4 is a cross-sectional view taken along line 4-4 in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, a centrifugal compressor according to one embodiment will be described with reference to Figs. 1 to 4. The centrifugal compressor of this embodiment is mounted on a vehicle (not shown) and used in the refrigeration cycle of a vehicle air conditioner. The centrifugal compressor compresses a refrigerant as a fluid.

[0019] <Basic configuration of a centrifugal compressor> As shown in Fig. 1, a centrifugal compressor 10 includes a rotating shaft 11, a compression mechanism 12, a motor 13, an inverter 14, and a housing 15. The compression mechanism 12 includes a first impeller 16 as an impeller, a suction chamber 17, a first diffuser 18 as a diffuser, and a first volute 19 as a volute. The compression mechanism 12 compresses the refrigerant as the rotating shaft 11 rotates. The motor 13 rotates the rotating shaft 11. The inverter 14 drives the motor 13.

[0020] The housing 15 is cylindrical. The housing 15 has a motor housing member 21, an impeller housing member 22, a suction housing member 23, and an inverter housing member 24. The housing 15 also has a first plate 25, a second plate 26, a third plate 27, and a fourth plate 28. The motor housing member 21, the impeller housing member 22, the suction housing member 23, the inverter housing member 24, the first plate 25, the second plate 26, the third plate 27, and the fourth plate 28 are made of a metal material, for example, aluminum.

[0021] The motor housing member 21 has a plate-shaped end wall 21a, a cylindrical first peripheral wall 21b, and a cylindrical second peripheral wall 21c. The end wall 21a has a circular shaft insertion hole 21d. The shaft insertion hole 21d is formed in the center of the end wall 21a. The shaft insertion hole 21d penetrates the end wall 21a in the thickness direction of the end wall 21a. The first peripheral wall 21b extends from the outer periphery of one surface of the end wall 21a in the thickness direction of the end wall 21a. The second peripheral wall 21c extends from the outer periphery of the other surface of the end wall 21a in the thickness direction of the end wall 21a.

[0022] As shown in FIG. 2, the impeller housing member 22 has a first housing member 29 and a second housing member 30. The first housing member 29 is plate-shaped. The first housing member 29 is connected to the motor housing member 21 while closing the opening of the first peripheral wall 21b. The end wall 21a of the motor housing member 21, the first peripheral wall 21b, and the first housing member 29 of the impeller housing member 22 define a motor chamber S1. The motor 13 is accommodated in the motor chamber S1. Therefore, the motor housing member 21 accommodates the motor 13.

[0023] The first housing member 29 has a circular shaft insertion hole 29a. The shaft insertion hole 29a is formed in the center of the first housing member 29. The shaft insertion hole 29a penetrates the first housing member 29 in the thickness direction of the first housing member 29. The axis of the shaft insertion hole 29a coincides with the axis of the shaft insertion hole 21d.

[0024] The second housing member 30 is plate-shaped and is connected to an end face of the first housing member 29 opposite to the motor housing member 21. The second housing member 30 is connected to the first housing member 29 with the thickness direction of the second housing member 30 and the thickness direction of the first housing member 29 aligned with each other.

[0025] The second housing member 30 has a circular hole-shaped first suction port 31. The first suction port 31 is formed in the center of the second housing member 30. The first suction port 31 opens on the end face of the second housing member 30 opposite to the first housing member 29. The second housing member 30 is connected to the first housing member 29 with the axis of the first suction port 31 coinciding with the axis of the shaft insertion hole 29a.

[0026] A first impeller chamber 32 is formed between the first housing member 29 and the second housing member 30. Therefore, the first housing member 29 and the second housing member 30 define the first impeller chamber 32. The first impeller chamber 32 communicates with the first suction port 31. The first impeller chamber 32 houses the first impeller 16. Therefore, the impeller housing member 22 houses the first impeller 16.

[0027] The suction housing member 23 is connected to the end face of the second housing member 30 opposite to the first housing member 29. The suction housing member 23 has a chamber-forming recess 33. The chamber-forming recess 33 opens at the end face of the suction housing member 23 facing the second housing member 30. The second housing member 30 closes the opening of the chamber-forming recess 33. The chamber-forming recess 33 and the second housing member 30 define the suction chamber 17. Therefore, the suction housing member 23 defines the suction chamber 17. The suction chamber 17 is in communication with the first suction port 31.

[0028] As shown in FIG. 1 , the inverter housing member 24 includes a housing main body 24a and a lid member 24b. The housing main body 24a is cylindrical. The housing main body 24a is connected to an end face of the suction housing member 23 opposite the second housing member 30. An opening on the first end side of the housing main body 24a is closed by an end face of the suction housing member 23 opposite the second housing member 30. The lid member 24b is connected to the housing main body 24a while closing an opening on the second end side of the housing main body 24a. The housing main body 24a, the lid member 24b, and the suction housing member 23 define an inverter chamber 34. The inverter 14 is housed in the inverter chamber 34. Thus, the inverter housing member 24 houses the inverter 14.

[0029] The first plate 25 is connected to the motor housing member 21 while closing the opening of the second peripheral wall 21c of the motor housing member 21. A bearing accommodating chamber 35 is defined by the end wall 21a, the second peripheral wall 21c of the motor housing member 21, and the first plate 25. The bearing accommodating chamber 35 communicates with the shaft insertion hole 21d. A thrust bearing 36 is accommodated in the bearing accommodating chamber 35.

[0030] The first plate 25 has a circular hole-shaped second suction port 37. The second suction port 37 is formed in the center of the first plate 25. The second suction port 37 opens at the end surface of the first plate 25 facing the motor housing member 21. The first plate 25 is connected to the motor housing member 21 with the axis of the second suction port 37 coinciding with the axis of the shaft insertion hole 21d.

[0031] The second plate 26 is connected to the end face of the first plate 25 opposite to the motor housing member 21. The second plate 26 is connected to the first plate 25 in a state where the thickness direction of the second plate 26 and the thickness direction of the first plate 25 coincide with each other.

[0032] The second plate 26 has a shaft insertion hole 26a. The shaft insertion hole 26a is formed in the center of the second plate 26. The shaft insertion hole 26a penetrates the second plate 26 in the thickness direction of the second plate 26. The axis of the shaft insertion hole 26a coincides with the axis of the second intake port 37.

[0033] A second impeller chamber 38 is formed between the first plate 25 and the second plate 26. Therefore, the first plate 25 and the second plate 26 define the second impeller chamber 38. The second impeller chamber 38 communicates with the second suction port 37. The second impeller chamber 38 also communicates with the shaft insertion hole 26a.

[0034] The third plate 27 is connected to the end face of the second plate 26 opposite to the first plate 25. The third plate 27 is connected to the second plate 26 in a state where the thickness direction of the third plate 27 and the thickness direction of the second plate 26 coincide with each other.

[0035] The third plate 27 has a circular third suction port 39. The third suction port 39 is formed in the center of the third plate 27. The third suction port 39 opens on the end face of the third plate 27 opposite to the second plate 26. The third plate 27 is connected to the second plate 26 with the axis of the third suction port 39 coinciding with the axis of the shaft insertion hole 26a.

[0036] A third impeller chamber 40 is formed between the second plate 26 and the third plate 27. Therefore, the second plate 26 and the third plate 27 define the third impeller chamber 40. The third impeller chamber 40 communicates with the third suction port 39. The third impeller chamber 40 also communicates with the shaft insertion hole 26a.

[0037] The fourth plate 28 is connected to the end face of the third plate 27 opposite to the second plate 26. The fourth plate 28 closes the opening of the third suction port 39 in the axial direction of the third suction port 39.

[0038] The rotating shaft 11 is accommodated in the housing 15. A first end of the rotating shaft 11 is located in the first impeller chamber 32. The rotating shaft 11 passes through the shaft insertion hole 29a, the motor chamber S1, the shaft insertion hole 21d, the bearing accommodating chamber 35, the second intake port 37, the second impeller chamber 38, and the shaft insertion hole 26a. A second end of the rotating shaft 11 is located in the third impeller chamber 40.

[0039] A first impeller 16 is connected to a first end of the rotary shaft 11. The centrifugal compressor 10 also includes a second impeller 41 and a third impeller 42. The second impeller 41 is housed in a second impeller chamber 38. The third impeller 42 is housed in a third impeller chamber 40. The second impeller 41 and the third impeller 42 are connected to a second end of the rotary shaft 11. The first impeller 16, the second impeller 41, and the third impeller 42 rotate integrally with the rotary shaft 11.

[0040] The first impeller 16 rotates integrally with the rotary shaft 11 to compress the refrigerant drawn into the first impeller chamber 32 from the first suction port 31. The second impeller 41 rotates integrally with the rotary shaft 11 to compress the refrigerant drawn into the second impeller chamber 38 from the second suction port 37. The third impeller 42 rotates integrally with the rotary shaft 11 to compress the refrigerant drawn into the third impeller chamber 40 from the third suction port 39.

[0041] The motor housing member 21, the impeller housing member 22, the suction housing member 23, and the inverter housing member 24 are arranged side by side in this order in the axial direction of the rotating shaft 11. The housing 15 accommodates the motor 13, the compression mechanism 12, and the inverter 14, all of which are arranged side by side in this order in the axial direction of the rotating shaft 11. The suction chamber 17 is provided on the inverter 14 side of the first impeller 16 in the axial direction of the rotating shaft 11.

[0042] A first radial bearing 43 is provided between the shaft insertion hole 21d and the rotating shaft 11. The first radial bearing 43 supports the rotating shaft 11 so that it can rotate in the radial direction. A second radial bearing 44 is provided between the shaft insertion hole 29a and the rotating shaft 11. The second radial bearing 44 supports the rotating shaft 11 so that it can rotate in the radial direction.

[0043] The centrifugal compressor 10 includes a thrust collar 45. The thrust collar 45 is disk-shaped. The thrust collar 45 protrudes from the outer peripheral surface of the rotating shaft 11. The thrust collar 45 is press-fitted into the outer peripheral surface of the rotating shaft 11. The thrust collar 45 rotates integrally with the rotating shaft 11. The thrust collar 45 is disposed in the bearing accommodating chamber 35. The thrust bearing 36 supports the rotating shaft 11 via the thrust collar 45 so as to be rotatable in the thrust direction.

[0044] 2, the first diffuser 18 and the first volute 19 are formed between the first housing member 29 and the second housing member 30. Therefore, the impeller housing member 22 defines the first diffuser 18 and the first volute 19. The first diffuser 18 is disposed downstream of the first impeller 16 in the refrigerant flow direction. The first volute 19 extends around the central axis of the first suction port 31 around the first impeller chamber 32. The first volute 19 communicates with the outlet of the first diffuser 18 and is provided on the radial outer periphery of the rotary shaft 11.

[0045] As shown in Fig. 1, the centrifugal compressor 10 includes a second diffuser 46 and a second volute 47. The second diffuser 46 and the second volute 47 are formed between the first plate 25 and the second plate 26. Therefore, the first plate 25 and the second plate 26 define the second diffuser 46 and the second volute 47. The second diffuser 46 is disposed downstream of the second impeller 41 in the refrigerant flow direction. The second volute 47 extends around the central axis of the second suction port 37 around the second impeller chamber 38. The second volute 47 is in communication with the outlet of the second diffuser 46 and is provided on the radial outer periphery of the rotary shaft 11.

[0046] The centrifugal compressor 10 includes a third diffuser 48 and a third volute 49. The third diffuser 48 and the third volute 49 are formed between the second plate 26 and the third plate 27. Therefore, the second plate 26 and the third plate 27 define the third diffuser 48 and the third volute 49. The third diffuser 48 is disposed downstream of the third impeller 42 in the refrigerant flow direction. The third volute 49 extends around the central axis of the third suction port 39 around the third impeller chamber 40. The third volute 49 communicates with the outlet of the third diffuser 48 and is provided on the radial outer periphery of the rotary shaft 11.

[0047] The centrifugal compressor 10 has a first communication hole 50. The first communication hole 50 is formed in the first housing member 29. A first end of the first communication hole 50 communicates with the first volute 19. A second end of the first communication hole 50 communicates with the motor chamber S1. The centrifugal compressor 10 has a plurality of second communication holes 51. Each second communication hole 51 is formed in the end wall 21a of the motor housing member 21. A first end of each second communication hole 51 communicates with the motor chamber S1. A second end of each second communication hole 51 communicates with the bearing accommodating chamber 35.

[0048] The centrifugal compressor 10 has a third communication hole 52. The third communication hole 52 penetrates the second plate 26 and the third plate 27. A first end of the third communication hole 52 communicates with the second volute 47. A second end of the third communication hole 52 opens to an end face of the third plate 27 opposite to the second plate 26. The centrifugal compressor 10 has a communication groove 53. The communication groove 53 is formed in an end face of the third plate 27 opposite to the second plate 26. The communication groove 53 extends in the radial direction of the rotating shaft 11. The communication groove 53 is closed by the fourth plate 28. A communication passage 54 is defined by the communication groove 53 and the fourth plate 28. A first end of the communication passage 54 communicates with a second end of the third communication hole 52. A second end of the communication passage 54 communicates with the third suction port 39.

[0049] The motor 13 includes a stator 55 and a rotor 56. The stator 55 has a cylindrical stator core 57 and a coil 58 wound around the stator core 57. The stator core 57 is fixed to the inner circumferential surface of the first circumferential wall 21b of the motor housing member 21. The rotor 56 is disposed inside the stator core 57 in the motor chamber S1. The rotor 56 rotates integrally with the rotating shaft 11. The rotor 56 has a rotor core 59 fixed to the rotating shaft 11 and a plurality of permanent magnets (not shown) provided on the rotor core 59.

[0050] <First Volute> As shown in FIG. 3 , the first volute 19 has a scroll passage 60 and a discharge passage 61. The scroll passage 60 extends in a spiral shape around the axis L1 of the rotary shaft 11 in the circumferential direction of the rotary shaft 11. The scroll passage 60 is connected to the outlet of the first diffuser 18. The scroll passage 60 surrounds the first diffuser 18. The scroll passage 60 extends around the entire circumferential direction of the rotary shaft 11 on the radial outer periphery of the rotary shaft 11. The scroll passage 60 has a minimum passage section 60a, which is the part of the scroll passage 60 with the smallest passage cross-sectional area, and a maximum passage section 60b, which is the part of the scroll passage 60 with the largest passage cross-sectional area. The passage cross-sectional area of ​​the scroll passage 60 gradually increases from the minimum passage section 60a in the circumferential direction of the rotary shaft 11 until it reaches the maximum passage section 60b. The minimum passage section 60a and the maximum passage section 60b are connected to each other.

[0051] The discharge flow path 61 branches off from the scroll flow path 60 and extends in the circumferential direction of the rotary shaft 11 around the axis L1 of the rotary shaft 11, radially outward of the scroll flow path 60. The discharge flow path 61 branches off from the maximum flow path section 60b of the scroll flow path 60. Therefore, the connection point of the discharge flow path 61 with the maximum flow path section 60b is also a branch point 62 of the discharge flow path 61 from the scroll flow path 60.

[0052] Here, when viewed from the axial direction of the rotating shaft 11, a straight line that passes through the axis L1 of the rotating shaft 11 and passes through a branch point 62 in the discharge flow path 61 where the scroll flow path 60 branches off is defined as an imaginary straight line L10. Further, when viewed from the axial direction of the rotating shaft 11, a straight line that passes through the axis L1 of the rotating shaft 11 and extends in a direction perpendicular to the imaginary straight line L10 is defined as an orthogonal line L11. The discharge flow path 61 extends from the branch point 62 located on the imaginary straight line L10 toward the orthogonal line L11. The discharge flow path 61 extends from the imaginary straight line L10 toward the orthogonal line L11 without crossing the orthogonal line L11.

[0053] <Suction chamber> As shown in Figures 3 and 4, the suction chamber 17 overlaps and covers the first impeller 16, the first diffuser 18, and the first volute 19 when viewed in the axial direction of the rotary shaft 11. Also, as shown in Figure 4, the centrifugal compressor 10 is provided with a suction passage 63. The suction passage 63 is formed in the suction housing member 23. The suction passage 63 extends in the radial direction of the rotary shaft 11. A first end of the suction passage 63 communicates with the outside of the suction housing member 23. A second end of the suction passage 63 communicates with the suction chamber 17. Therefore, the suction passage 63 connects the suction chamber 17 to the outside of the housing 15. The suction passage 63 draws refrigerant outside the housing 15 into the suction chamber 17.

[0054] <Through hole> 2, a through hole 64 is formed in the housing 15. The through hole 64 passes through the motor housing member 21, the impeller housing member 22, and the suction housing member 23 in the axial direction of the rotating shaft 11, and communicates with the inside of the inverter housing member 24.

[0055] As shown in FIG. 3 , the through hole 64 has a rectangular hole shape. The through hole 64 is disposed at a distance from the first volute 19. The through hole 64 is disposed at a position separated from the suction passage 63. Therefore, the suction passage 63 is provided at a position separated from the through hole 64 in the circumferential direction of the rotary shaft 11. The through hole 64 is disposed on an extension line of the rotary shaft 11 along which the discharge passage 61 extends. Note that the extension line of the rotary shaft 11 along which the discharge passage 61 extends passes through an imaginary circle C1 whose center is the axis L1 of the rotary shaft 11. When viewed in the axial direction of the rotary shaft 11, the through hole 64 is located on the same side as the discharge passage 61 with respect to an imaginary line L10, and is adjacent to the downstream end of the discharge passage 61 in the circumferential direction of the rotary shaft 11.

[0056] <Wiring section> As shown in FIG. 2 , the centrifugal compressor 10 includes a wiring unit 65. The wiring unit 65 includes a conductive member 66, motor wiring 67, and a cluster block 68. The conductive member 66 is cylindrical. The conductive member 66 is supported by the housing 15 via a support member 69. Specifically, the support member 69 is plate-shaped. The support member 69 is disposed in the inverter chamber 34. The support member 69 is fixed to the end face of the suction housing member 23 opposite to the second housing member 30. The support member 69 supports the conductive member 66. A first end of the conductive member 66 is electrically connected to the inverter 14. A second end of the conductive member 66 is inserted into the through hole 64. Therefore, the conductive member 66 extends from the inverter 14 into the through hole 64.

[0057] The motor wiring 67 is drawn out from the coil 58 of the motor 13. Therefore, the motor wiring 67 is drawn out from the motor 13. The cluster block 68 is made of resin. The cluster block 68 is in the shape of a rectangular box. The cluster block 68 houses a connection terminal 68a. A second end of the conductive member 66 is connected to the connection terminal 68a. The motor wiring 67 drawn out from the coil 58 is also connected to the connection terminal 68a. Therefore, the connection terminal 68a electrically connects the conductive member 66 and the motor wiring 67.

[0058] The cluster block 68 is disposed in the through-hole 64. Therefore, the wiring portion 65 is provided in the housing 15 and inserted into the through-hole 64. In this way, the wiring portion 65 electrically connects the motor 13 and the inverter 14. Then, power controlled by the inverter 14 is supplied to the coil 58 via the conductive member 66, the connection terminal 68a, and the motor wiring 67, causing the rotor 56 to rotate. As a result, the rotating shaft 11 rotates integrally with the rotor 56.

[0059] <Refrigerant flow> In the centrifugal compressor 10, when the rotating shaft 11 rotates, the rotation of the first impeller 16 causes refrigerant to be drawn into the first impeller chamber 32 from outside the housing 15 through the suction passage 63, the suction chamber 17, and the first suction port 31. The refrigerant drawn into the first impeller chamber 32 is sent from the first impeller chamber 32 to the first diffuser 18 by centrifugal action caused by the rotation of the first impeller 16, and is pressurized by the first diffuser 18. The refrigerant that has passed through the first diffuser 18 is then discharged to the first volute 19.

[0060] The refrigerant discharged to the first volute 19 flows into the motor chamber S1 through the first communication holes 50. As the second impeller 41 rotates, the refrigerant in the motor chamber S1 is drawn into the second impeller chamber 38 through the second communication holes 51, the bearing accommodating chamber 35, and the second suction port 37. The refrigerant drawn into the second impeller chamber 38 is sent from the second impeller chamber 38 to the second diffuser 46 by centrifugal action caused by the rotation of the second impeller 41, and is pressurized by the second diffuser 46. The refrigerant that has passed through the second diffuser 46 is then discharged into the second volute 47.

[0061] The refrigerant discharged to the second volute 47 is drawn into the third impeller chamber 40 through the third communication hole 52, the communication passage 54, and the third suction port 39 as the third impeller 42 rotates. The refrigerant drawn into the third impeller chamber 40 is sent from the third impeller chamber 40 to the third diffuser 48 by centrifugal action caused by the rotation of the third impeller 42, and is pressurized by the third diffuser 48. The refrigerant that has passed through the third diffuser 48 is then discharged to the third volute 49. The refrigerant discharged to the third volute 49 is discharged outside the housing 15 and supplied to the fuel cell.

[0062] [Operation of the embodiment] Next, the operation of this embodiment will be described. Heat generated by inverter 14 is dissipated to the refrigerant in suction chamber 17 through suction housing member 23. As a result, inverter 14 is cooled by the refrigerant in suction chamber 17. Furthermore, the heat of the refrigerant passing through first diffuser 18 as first impeller 16 rotates and the refrigerant discharged from the outlet of first diffuser 18 to first volute 19 is dissipated by the refrigerant in suction chamber 17. Therefore, the heat of the refrigerant passing through first diffuser 18 as first impeller 16 rotates and the refrigerant discharged from the outlet of first diffuser 18 to first volute 19 is not easily transferred to inverter 14 through suction housing member 23.

[0063] [Effects of the embodiment] The above embodiment can provide the following effects. (1) The through hole 64 passes through the motor housing member 21, the impeller housing member 22, and the suction housing member 23 in the axial direction of the rotating shaft 11 and communicates with the inside of the inverter housing member 24. The wiring portion 65 is provided in the housing 15 and inserted into the through hole 64. Therefore, the wiring portion 65 can electrically connect the motor 13 and the inverter 14 without extending outside the housing 15. This eliminates the need for a seal member between the wiring portion 65 and the housing 15, which would be necessary if the wiring portion 65 extended outside the housing 15. Furthermore, unlike the case where the wiring portion 65 extends outside the housing 15, it is no longer necessary to fix the wiring portion 65 to the housing 15 to prevent the wiring portion 65 from interfering with accessories arranged around the centrifugal compressor 10. This eliminates an increase in the number of parts and a deterioration in mountability.

[0064] Furthermore, the through hole 64 is disposed at a distance from the first volute 19, and the suction passage 63 is provided at a position spaced apart from the through hole 64 in the circumferential direction of the rotary shaft 11. As a result, even if the through hole 64 for inserting the wiring portion 65 is formed to penetrate the impeller housing member 22 and the suction housing member 23 in the axial direction of the rotary shaft 11, the through hole 64 does not affect the designs of the first volute 19 and the suction passage 63, which are existing configurations. Therefore, to form the through hole 64 to penetrate the impeller housing member 22 and the suction housing member 23 in the axial direction of the rotary shaft 11, it is not necessary to change the positions of the first volute 19 and the suction passage 63, for example. This makes it possible to avoid a problem in which the overall size of the centrifugal compressor 10 increases when the positions of the first volute 19 and the suction passage 63 are changed. As a result, the motor 13 and the inverter 14 can be electrically connected without increasing the number of parts or deteriorating the mountability, while avoiding an increase in the overall size of the centrifugal compressor 10.

[0065] (2) The through hole 64 is disposed on a circumferential extension of the rotating shaft 11 along which the discharge flow path 61 extends. This makes it possible to prevent the overall size of the centrifugal compressor 10 from increasing in size, compared to when the through hole 64 is disposed, for example, radially outward of the rotating shaft 11 from a circumferential extension of the rotating shaft 11 along which the discharge flow path 61 extends. Therefore, the motor 13 and the inverter 14 can be electrically connected without increasing the number of parts or deteriorating mountability, while preventing the overall size of the centrifugal compressor 10 from increasing in size.

[0066] (3) In the impeller housing member 22, a portion located on the same side of the imaginary line L10 as the discharge passage 61, as viewed in the axial direction of the rotary shaft 11, and adjacent to the downstream end of the discharge passage 61 in the circumferential direction of the rotary shaft 11, is a dead space. Here, the through hole 64 is located on the same side of the imaginary line L10 as the discharge passage 61, as viewed in the axial direction of the rotary shaft 11, and adjacent to the downstream end of the discharge passage 61 in the circumferential direction of the rotary shaft 11. Therefore, the portion that is a dead space in the impeller housing member 22 is effectively used as an arrangement space for the through hole 64. Therefore, there is no need to provide a separate arrangement space for the through hole 64 in the impeller housing member 22, and therefore it is possible to avoid an increase in the size of the entire centrifugal compressor 10 due to the provision of the through hole 64.

[0067] (4) When viewed in the axial direction of the rotary shaft 11, the suction chamber 17 overlaps and covers the first impeller 16, the first diffuser 18, and the first volute 19. This facilitates heat dissipation to the refrigerant in the suction chamber 17 from the refrigerant passing through the first diffuser 18 as the first impeller 16 rotates and from the refrigerant discharged from the outlet of the first diffuser 18 to the first volute 19. This reduces the heat transfer to the inverter 14 via the housing 15 from the refrigerant passing through the first diffuser 18 as the first impeller 16 rotates and from the refrigerant discharged from the outlet of the first diffuser 18 to the first volute 19. This improves the reliability of the inverter 14. Furthermore, since the volume of the suction chamber 17 can be maximized, the pulsation of the refrigerant drawn into the suction chamber 17 can be reduced.

[0068] (5) The cluster block 68 is disposed inside the through hole 64. This allows the through hole 64 to be effectively used as an arrangement space for the cluster block 68, which is an existing configuration. Therefore, there is no need to provide a separate arrangement space for the cluster block 68, and the overall size of the centrifugal compressor 10 can be reduced.

[0069] [Example of change] The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

[0070] In the above embodiment, the through-hole 64 may be disposed radially outward of the rotary shaft 11 from the circumferential extension of the rotary shaft 11 along which the discharge passage 61 extends. In the above embodiment, the through-hole 64 may be located on the opposite side of the imaginary line L10 from the discharge passage 61 when viewed in the axial direction of the rotary shaft 11.

[0071] In the embodiment, the suction chamber 17 does not have to cover or overlap a portion of the first volute 19 when viewed in the axial direction of the rotary shaft 11 .

[0072] In the above embodiment, the suction chamber 17 does not have to cover or overlap a portion of the first diffuser 18 when viewed in the axial direction of the rotary shaft 11 .

[0073] In the embodiment, the cluster block 68 may not be disposed inside the through hole 64, but may be disposed, for example, inside the motor chamber S1. Even in this case, the conductive member 66 is inserted into the through hole 64. The key point is that the wiring portion 65 is inserted into the through hole 64.

[0074] In the above-described embodiment, the centrifugal compressor 10 may not include the third impeller 42, for example. In the above-described embodiment, the centrifugal compressor 10 may not include the second impeller 41 and the third impeller 42, for example.

[0075] In the embodiment, the fluid compressed by the rotation of each of the first impeller 16, the second impeller 41, and the third impeller 42 is not limited to a refrigerant. Therefore, the centrifugal compressor 10 can be applied to any object and any fluid to be compressed. For example, the centrifugal compressor 10 may be mounted on a fuel cell vehicle. The fuel cell vehicle is equipped with a fuel cell system that supplies oxygen and hydrogen to a fuel cell to generate electricity. The centrifugal compressor compresses air as a fluid containing oxygen to be supplied to the fuel cell. Furthermore, for example, the centrifugal compressor 10 may be applied to a refrigerant circuit for regulating the temperature of a battery. The centrifugal compressor 10 can be mounted on any object and is not limited to a vehicle.

[0076] [Note] The technical ideas that can be understood from the above-described embodiment and modifications will be described below. <Appendix 1> A rotation axis; a compression mechanism that compresses a fluid in accordance with rotation of the rotary shaft; a motor that rotates the rotary shaft; an inverter that drives the motor; a housing that accommodates the motor, the compression mechanism, and the inverter in a state where they are arranged side by side in this order in the axial direction of the rotating shaft, The compression mechanism includes: an impeller that rotates integrally with the rotary shaft; a suction chamber provided on the inverter side in the axial direction with respect to the impeller; a diffuser disposed downstream of the impeller in the direction of flow of the fluid; a volute communicating with an outlet of the diffuser and provided on an outer periphery of the rotary shaft in the radial direction, A centrifugal compressor including a wiring unit that electrically connects the motor and the inverter, the housing includes a motor housing member that accommodates the motor, an impeller housing member that accommodates the impeller and that defines the diffuser and the volute, an intake housing member that defines the intake chamber, and an inverter housing member that accommodates the inverter, the motor housing member, the impeller housing member, the suction housing member, and the inverter housing member are arranged side by side in this order in the axial direction, a through hole is formed in the housing, the through hole passing through the motor housing member, the impeller housing member, and the suction housing member in the axial direction and communicating with the inside of the inverter housing member; the wiring portion is provided in the housing and is inserted into the through hole, The through hole is disposed away from the volute, a suction passage connecting the suction chamber with the outside of the housing, the suction passage being located at a position spaced apart from the through hole in the circumferential direction of the rotary shaft;

[0077] <Appendix 2> The volute is a scroll flow path extending spirally in the circumferential direction around the axis of the rotary shaft; a discharge flow path that branches off from the scroll flow path and extends in the circumferential direction around the axis of the rotary shaft at a position radially outward of the scroll flow path, The centrifugal compressor according to <Supplementary Note 1>, wherein the through-hole is arranged on an extension line of the discharge flow path in the circumferential direction.

[0078] <Appendix 3> When viewed from the axial direction, a straight line passing through the axis of the rotation shaft and passing through a branch point of the discharge flow path from the scroll flow path is defined as a virtual straight line. The centrifugal compressor according to <Appendix 2>, wherein the through hole is located on the same side as the discharge flow path with respect to the imaginary line as viewed in the axial direction, and is adjacent to a downstream end of the discharge flow path in the circumferential direction.

[0079] <Appendix 4> The centrifugal compressor according to any one of <Appendix 1> to <Appendix 3>, wherein the suction chamber overlaps and covers the impeller, the diffuser, and the volute when viewed from the axial direction.

[0080] <Appendix 5> The wiring portion is a conductive member extending from the inverter into the through hole; a motor wiring drawn out from the motor; a cluster block that houses a connection terminal that electrically connects the conductive member and the motor wiring, The centrifugal compressor according to any one of <Supplementary Note 1> to <Supplementary Note 4>, wherein the cluster block is disposed inside the through hole. [Explanation of symbols]

[0081] 10...centrifugal compressor, 11...rotating shaft, 12...compression mechanism, 13...motor, 14...inverter, 15...housing, 16...first impeller as impeller, 17...suction chamber, 18...first diffuser as diffuser, 19...first volute as volute, 21...motor housing member, 22...impeller housing member, 23...suction housing member, 24...inverter housing member, 60...scroll flow path, 61...discharge flow path, 62...branching point, 63...suction passage, 64...through hole, 65...wiring portion, 66...conductive member, 67...motor wiring, 68...cluster block, 68a...connection terminal.

Claims

1. A rotation axis; a compression mechanism that compresses a fluid in accordance with rotation of the rotary shaft; a motor that rotates the rotary shaft; an inverter that drives the motor; a housing that accommodates the motor, the compression mechanism, and the inverter in a state where they are arranged side by side in this order in the axial direction of the rotating shaft, The compression mechanism includes: an impeller that rotates integrally with the rotary shaft; a suction chamber provided on the inverter side in the axial direction with respect to the impeller; a diffuser disposed downstream of the impeller in the direction of flow of the fluid; a volute communicating with an outlet of the diffuser and provided on an outer periphery of the rotary shaft in the radial direction, A centrifugal compressor including a wiring unit that electrically connects the motor and the inverter, the housing includes a motor housing member that accommodates the motor, an impeller housing member that accommodates the impeller and that defines the diffuser and the volute, an intake housing member that defines the intake chamber, and an inverter housing member that accommodates the inverter, the motor housing member, the impeller housing member, the suction housing member, and the inverter housing member are arranged side by side in this order in the axial direction, a through hole is formed in the housing, the through hole passing through the motor housing member, the impeller housing member, and the suction housing member in the axial direction and communicating with the inside of the inverter housing member; the wiring portion is provided in the housing and is inserted into the through hole, The through hole is disposed away from the volute, a suction passage connecting the suction chamber with the outside of the housing, the suction passage being located at a position spaced apart from the through hole in the circumferential direction of the rotary shaft;

2. The volute is a scroll flow path extending spirally in the circumferential direction around the axis of the rotary shaft; a discharge flow path that branches off from the scroll flow path and extends in the circumferential direction around the axis of the rotary shaft at a position radially outward of the scroll flow path, The centrifugal compressor according to claim 1, wherein the through-holes are arranged on an extension line of the discharge flow passage in the circumferential direction.

3. When viewed from the axial direction, a straight line passing through the axis of the rotation shaft and passing through a branch point of the discharge flow path from the scroll flow path is defined as a virtual straight line.

3. The centrifugal compressor according to claim 2, wherein the through hole is located on the same side as the discharge flow path with respect to the imaginary line when viewed from the axial direction, and is adjacent to a downstream end of the discharge flow path in the circumferential direction.

4. 4. The centrifugal compressor according to claim 1, wherein the suction chamber overlaps with and covers the impeller, the diffuser, and the volute when viewed from the axial direction.

5. The wiring portion is a conductive member extending from the inverter into the through hole; a motor wiring drawn out from the motor; a cluster block that houses a connection terminal that electrically connects the conductive member and the motor wiring, 4. The centrifugal compressor according to claim 1, wherein the cluster block is disposed within the through hole.

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