Fluid Machinery

Abstract

The present invention provides a fluid machine that suppresses the reduction in cooling efficiency caused by a cooling fluid. After the cooling fluid is introduced into the inverter cooling flow path (31), it branches into a fluid flow flowing in the inverter cooling flow path (31) and a fluid flow flowing in the motor cooling flow path (32) at an inlet (35). The fluid flow flowing in the inverter cooling flow path (31) and the fluid flow flowing in the motor cooling flow path (32) merge at an outlet (36) and are discharged from the inverter cooling flow path (31). The inverter cooling flow path (31) has a second flow path (39) that generates a vortex, and the outlet (36) is provided in the second flow path (39). A vortex is generated in the inverter cooling flow path (31) and a slight pressure loss occurs. Therefore, compared with a case where no vortex is generated, for example, the cooling fluid flowing in the motor cooling flow path (32) is more likely to merge with the second flow path (39) via the outlet (36).

Description

Technical Field

[0001] The present invention relates to fluid machinery. Background Art

[0002] For example, a fluid machine driven by an electric motor, such as an electric compressor, includes a rotating shaft, an electric motor that rotates the rotating shaft, a pump unit that pressurizes and delivers a fluid through the rotation of the rotating shaft, and an inverter that drives the electric motor. In addition, the electric compressor includes a housing having a motor chamber that accommodates the electric motor and an inverter chamber that accommodates the inverter. For example, Patent Document 1 discloses a structure in which the inverter chamber is arranged radially outside the rotating shaft relative to the motor chamber, and a cooling flow path is formed in the housing in a partition that separates the motor chamber from the inverter chamber. Thus, the electric motor and the inverter are cooled by the cooling fluid flowing in the cooling flow path.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2020-162187 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] However, it is desirable to efficiently cool the electric motor and inverter using the cooling fluid flowing in the cooling flow path formed in the housing even in a case where, for example, the motor chamber and the inverter chamber are arranged in the axial direction of the rotating shaft. In such a structure, in order to efficiently cool the electric motor and the inverter, it is necessary to form a cooling flow path not only on the circumference of the electric motor but also on the end surface. However, if it is desired to form a cooling flow path with one flow path, the flow path becomes longer and pressure loss is likely to occur. If it is desired to form a cooling flow path in the form of branches to the circumference and end surface of the motor, the cooling fluid is likely to flow back from the flow path on one side to the flow path on the other side at the confluence portion, thereby reducing the cooling efficiency as a whole. Therefore, it is desirable to have a structure that suppresses the reduction in cooling efficiency.

[0008] Solutions to Problems

[0009] 18. The fluid machinery for solving the above-mentioned problems comprises: a rotating shaft; an electric motor which rotates the rotating shaft; a pump which pressurizes and delivers a fluid by the rotation of the rotating shaft; an inverter which drives the electric motor; and a housing which has a motor chamber for accommodating the electric motor and an inverter chamber for accommodating the inverter, the motor chamber and the inverter chamber being arranged in an axial direction of the rotating shaft, a cooling flow path for a cooling fluid for cooling the electric motor and the inverter being formed in the housing, the housing having: a plate-shaped partition which separates the motor chamber from the inverter chamber in the axial direction of the rotating shaft; and a peripheral wall portion which extends from the partition in a cylindrical shape in the axial direction of the rotating shaft and surrounds the electric motor, wherein the cooling flow path comprises: an inverter cooling flow path for a cooling fluid to flow inside the partition movement; and a motor cooling flow path, which supplies cooling fluid to flow inside the peripheral wall portion, one end of the motor cooling flow path is connected to the inverter cooling flow path at an inlet branch portion, so that the motor cooling flow path branches off from the inverter cooling flow path, and the other end of the motor cooling flow path is connected to the inverter cooling flow path at an outlet branch portion, so that the motor cooling flow path and the inverter cooling flow path merge, after being introduced into the inverter cooling flow path, the cooling fluid branches off at the inlet branch portion into a fluid flow flowing in the inverter cooling flow path and a fluid flow flowing in the motor cooling flow path, the fluid flow flowing in the inverter cooling flow path and the fluid flow flowing in the motor cooling flow path merge at the outlet branch portion and are discharged from the inverter cooling flow path, the inverter cooling flow path has a flow path expansion portion that generates a vortex, and the outlet branch portion is arranged at the flow path expansion portion.

[0010] Thus, the inverter is cooled by the cooling fluid flowing in the inverter cooling flow path. In addition, a portion of the cooling fluid flowing in the inverter cooling flow path branches from the inlet branch portion and flows in the motor cooling flow path. Furthermore, the cooling fluid flowing in the motor cooling flow path merges with the inverter cooling flow path at the outlet branch portion. At this time, the inverter cooling flow path has a flow path expansion portion that generates a vortex, and the outlet branch portion is provided at the flow path expansion portion. Thus, a vortex is generated in the inverter cooling flow path and a slight pressure loss occurs. Therefore, compared with a case where no vortex is generated, for example, the cooling fluid flowing in the motor cooling flow path easily merges with the flow path expansion portion via the outlet branch portion. Thus, the cooling fluid easily flows in the motor cooling flow path. As a result, it is possible to suppress a reduction in cooling efficiency.

[0011] In the above-mentioned fluid machinery, the inverter cooling flow path may extend inside the partition in a direction perpendicular to the rotating shaft, the motor cooling flow path may extend inside the peripheral wall along the axial direction of the rotating shaft, and the inlet branch and the outlet branch are arranged at the intersection of the partition and the peripheral wall in the shell.

[0012] This structure is preferred as it facilitates the formation of a cooling flow path with excellent cooling performance. Furthermore, in this structure, the motor cooling flow path branches and merges perpendicularly with the inverter cooling flow path. This makes it more likely that the cooling fluid will flow backwards at the merging point, which significantly increases the effectiveness of the flow path expansion portion.

[0013] Effects of the Invention

[0014] According to the present invention, it is possible to suppress a decrease in cooling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a side sectional view showing the electric compressor in the embodiment.

[0016] Figure 2 This is a schematic diagram showing a model of the cooling flow path.

[0017] Figure 3 This is a diagram of the flow path forming housing as viewed from the axial direction of the rotating shaft.

[0018] Figure 4 This is a diagram of the motor housing as viewed from the axial direction of the rotating shaft.

[0019] Figure 5 This is a diagram schematically showing the inverter cooling flow path and the motor cooling flow path in an expanded manner.

[0020] Description of Reference Numerals

[0021] 10…an electric compressor serving as a fluid machine; 11…a housing; 13b…a peripheral wall serving as a peripheral wall portion; 16…a rotating shaft; 17…an electric motor; 18…a motor chamber; 25…a compression portion serving as a pump portion; 28…an inverter; 29…an inverter chamber; 30…a cooling flow path; 31…an inverter cooling flow path; 32…a motor cooling flow path; 35…an inlet serving as an inlet branch portion; 36…an outlet serving as an outlet branch portion; 39…a second flow path serving as a flow path expansion portion; 50…a partition portion. DETAILED DESCRIPTION

[0022] The following, according to Figures 1 to 5 An embodiment in which the fluid machine is embodied as an electric compressor will be described. The electric compressor of this embodiment is used in, for example, a vehicle air conditioner.

[0023] like Figure 1 As shown, an electric compressor 10 as a fluid machine includes a housing 11. The housing 11 is cylindrical. The housing 11 includes a discharge housing 12, a motor housing 13, a flow path forming housing 14, and an inverter cover 15. The discharge housing 12, the motor housing 13, the flow path forming housing 14, and the inverter cover 15 are each made of a metal material, for example, aluminum.

[0024] The motor housing 13 has a plate-shaped end wall 13a and a peripheral wall 13b extending in a cylindrical shape from the outer periphery of the end wall 13a. The discharge housing 12 is connected to the motor housing 13 with the opening of the peripheral wall 13b of the motor housing 13 blocked. The discharge housing 12 is in the shape of a bottomed cylinder. The flow path forming housing 14 is connected to the outer surface of the end wall 13a of the motor housing 13. The flow path forming housing 14 is in the shape of a block. The inverter cover 15 is connected to the end surface of the flow path forming housing 14 on the side opposite to the motor housing 13. The inverter cover 15 is in the shape of a bottomed cylinder.

[0025] The electric compressor 10 includes a rotating shaft 16 . The rotating shaft 16 is housed in the motor housing 13 . The axial direction of the rotating shaft 16 coincides with the axial direction of the peripheral wall 13 b of the motor housing 13 .

[0026] The electric compressor 10 includes an electric motor 17. The electric motor 17 is housed in a motor chamber 18 formed inside the motor housing 13. Therefore, the housing 11 includes the motor chamber 18 for housing the electric motor 17. The electric motor 17 rotates the rotary shaft 16.

[0027] The electric motor 17 includes a stator 19 and a rotor 20. The stator 19 is cylindrical. The rotor 20 is arranged inside the stator 19. The rotor 20 includes a rotor core 21 fixed to the rotating shaft 16 and a plurality of permanent magnets 22 provided on the rotor core 21. The rotor 20 rotates integrally with the rotating shaft 16. The stator 19 includes a cylindrical stator core 23 and a coil 24 wound around the stator core 23. When power is supplied to the coil 24, the rotor 20 rotates, and the rotating shaft 16 and the rotor 20 rotate integrally.

[0028] The electric compressor 10 includes a compression section 25 serving as a pump unit. The compression section 25 is, for example, a scroll-type unit consisting of a fixed scroll (not shown) fixed within the motor housing 13 and a movable scroll (not shown) disposed opposite the fixed scroll. The compression section 25 compresses the refrigerant, which is a fluid, by utilizing the rotation of the rotating shaft 16. Furthermore, the compression section 25 pressurizes and transports the refrigerant by utilizing the rotation of the rotating shaft 16. The compression section 25 is disposed within the motor housing 13 at a position closer to the opening of the peripheral wall 13b than the electric motor 17. Therefore, the electric motor 17 is disposed at a position closer to the end wall 13a than the compression section 25.

[0029] A suction port 13h is formed in the peripheral wall 13b of the motor housing 13. The suction port 13h draws refrigerant into the motor housing 13. One end of the external refrigerant circuit 26 is connected to the suction port 13h. A discharge port 12h is formed in the discharge housing 12. The other end of the external refrigerant circuit 26 is connected to the discharge port 12h.

[0030] Refrigerant drawn into the motor housing 13 from the external refrigerant circuit 26 through the suction port 13h is compressed by the compressor 25 as it is driven, and flows out of the external refrigerant circuit 26 through the discharge port 12h. The refrigerant flowing out of the external refrigerant circuit 26 then passes through the heat exchanger and expansion valve of the external refrigerant circuit 26 and flows back into the motor housing 13 through the suction port 13h. The electric compressor 10 and the external refrigerant circuit 26 constitute a vehicle air conditioning system 27.

[0031] The electric compressor 10 includes an inverter 28. The inverter 28 drives the electric motor 17. The inverter 28 is housed in an inverter chamber 29 formed inside the inverter cover 15. Therefore, the housing 11 includes the inverter chamber 29 for housing the inverter 28.

[0032] The compression unit 25, electric motor 17, and inverter 28 are arranged in this order in the axial direction of the rotating shaft 16. Consequently, the motor chamber 18 and the inverter chamber 29 are arranged in the axial direction of the rotating shaft 16. The end wall 13a of the motor housing 13 and the flow path-forming case 14 form a plate-shaped partition 50 that separates the motor chamber 18 from the inverter chamber 29 in the axial direction of the rotating shaft 16. Furthermore, the peripheral wall 13b of the motor housing 13 functions as a peripheral wall portion that extends cylindrically from the partition 50 in the axial direction of the rotating shaft 16 and surrounds the electric motor 17.

[0033] A cooling flow path 30 is formed in the housing 11. Cooling fluid for cooling the electric motor 17 and the inverter 28 flows through the cooling flow path 30. The cooling flow path 30 includes an inverter cooling flow path 31 and a motor cooling flow path 32. The inverter cooling flow path 31 is formed in the partition 50. The inverter cooling flow path 31 extends perpendicularly to the rotating shaft 16 within the partition 50. Cooling fluid for cooling the inverter 28 flows through the inverter cooling flow path 31.

[0034] The motor cooling passage 32 is formed in the peripheral wall 13b of the motor housing 13. The motor cooling passage 32 extends from the end wall 13a of the motor housing 13 inside the peripheral wall 13b in the axial direction of the rotating shaft 16. A cooling fluid for cooling the electric motor 17 flows through the motor cooling passage 32. The motor cooling passage 32 is connected to the inverter cooling passage 31.

[0035] exist Figure 2In FIG, the motor cooling flow path 32 and the inverter cooling flow path 31 are modeled and shown. Figure 3 In FIG, the inverter cooling flow path 31 is observed from the axial direction of the rotating shaft 16. Figure 2 as well as Figure 3 As shown, the flow path forming case 14 has a supply port 33 and a discharge port 34. The supply port 33 supplies cooling fluid to the inverter cooling flow path 31. The discharge port 34 discharges the cooling fluid flowing through the inverter cooling flow path 31 to the outside.

[0036] like Figure 3 As shown, a flow path forming recess 141 for forming the inverter cooling flow path 31 is formed on the outer surface of the flow path forming housing 14. The flow path forming recess 141 is U-shaped when viewed from the axial direction of the rotating shaft. The bottom surface of the flow path forming recess 141 is a flat surface. The supply port 33 is connected to one end of the flow path forming recess 141. The discharge port 34 is connected to the other end of the flow path forming recess 141. In addition, when the outer surface of the flow path forming housing 14 is viewed from the axial direction of the rotating shaft, the portion of the outer surface of the flow path forming housing 14 other than the flow path forming recess 141 becomes a mating surface 142 that mates with the outer surface of the end wall 13a of the motor housing 13.

[0037] like Figure 4 As shown, a flow path forming recess 131 is formed on the outer surface of the motor housing 13, which forms the inverter cooling flow path 31. The flow path forming recess 131 is U-shaped when viewed axially along the rotating shaft. The bottom surface of the flow path forming recess 131 is flat. The flow path forming recess 131 of the motor housing 13 is shaped along the shape of the flow path forming recess 141 of the flow path forming housing 14. Furthermore, when viewed axially along the rotating shaft, the portion of the outer surface of the motor housing 13 other than the flow path forming recess 131 forms a mating surface 132.

[0038] like Figure 3 as well as Figure 4 As shown, the flow path-forming housing 14 and the motor housing 13 are connected to each other with the mating surface 142 of the flow path-forming housing 14 mating with the mating surface 132 of the motor housing 13. The inverter cooling flow path 31 is defined by the flow path-forming recess 141 of the flow path-forming housing 14 and the flow path-forming recess 131 of the motor housing 13. Therefore, the inverter cooling flow path 31 has a U-shape when viewed from the axial direction of the rotating shaft.

[0039] The motor housing 13 has an inlet 35, serving as an inlet branching portion, for allowing cooling fluid to flow from the inverter cooling passage 31 into the motor cooling passage 32; and an outlet 36, serving as an outlet branching portion, for allowing cooling fluid to flow from the motor cooling passage 32 into the inverter cooling passage 31. One end of the motor cooling passage 32 connects to the inverter cooling passage 31 at the inlet 35, thereby branching off from the inverter cooling passage 31. The other end of the motor cooling passage 32 connects to the inverter cooling passage 31 at the outlet 36, thereby merging the motor cooling passage 32 and the inverter cooling passage 31. The inlet 35 and outlet 36 open into the bottom surface of the passage-forming recess 131. The inlet 35 is located closer to the supply port 33 than the outlet 36. The inlet 35 and outlet 36 are located at the boundary between the end wall 13a and the peripheral wall 13b, which form part of the partition 50 in the housing 11.

[0040] The inverter cooling flow path 31 has a connecting flow path 37 that connects the inlet 35 and the outlet 36. Therefore, in the inverter cooling flow path 31, the inlet 35 and the outlet 36 are connected by the connecting flow path 37. In the inverter cooling flow path 31, the connecting flow path 37 extends from the position facing the inlet 35 to the position facing the outlet 36. The connecting flow path 37 includes a first flow path 38 connected to the inlet 35 and a second flow path 39 connected to the outlet 36. In the connecting flow path 37, the first flow path 38 is located upstream of the second flow path 39 in the flow direction of the cooling fluid in the inverter cooling flow path 31. The first flow path 38 connects the supply port 33 and the second flow path 39 in the inverter cooling flow path 31. In addition, the inverter cooling flow path 31 has a third flow path 40 that connects the second flow path 39 and the exhaust port 34. It should be noted that the motor housing 13 has an inlet 41 for allowing the cooling fluid flowing in the third flow path 40 to flow into the motor cooling flow path 32 , and an outlet 42 for allowing the cooling fluid flowing through the motor cooling flow path 32 to flow out to the third flow path 40 .

[0041] like Figure 3As shown, in the inverter cooling flow path 31, the first flow path 38 and the third flow path 40 are connected by the second flow path 39. When viewed from the axial direction of the rotating shaft 16, the width H1 of the second flow path 39 is approximately constant from the first flow path 38 to the third flow path 40. When viewed from the axial direction of the rotating shaft 16, the width H1 of the second flow path 39 is wider than the width H2 of the first flow path 38. Specifically, the width H1 of the second flow path 39 is wider than the width H2 of the outlet 38a of the first flow path 38. Because the flow path forming recess 141 and the flow path forming recess 131 are flat, the second flow path 39 is a flow path that expands compared to the first flow path 38 and functions as a flow path expansion portion that generates vortex flow. When viewed from the axial direction of the rotating shaft 16, the width of the second flow path 39 expands in a direction away from the inlet 40a of the third flow path 40. When viewed from the axial direction of the rotating shaft 16 , the width H1 of the second flow path 39 is wider than the width H3 of the third flow path 40 . Specifically, the width H1 of the second flow path 39 is wider than the width H3 of the inlet 40 a of the third flow path 40 .

[0042] Because flow path forming recess 141 and flow path forming recess 131 are flat, outflow port 36 falls within the projection area of ​​second flow path 39 when viewed from the axial direction of rotation shaft 16. Outflow port 36 communicates with second flow path 39 at a position away from third flow path 40. Therefore, outflow port 36 is provided in second flow path 39.

[0043] The flow path cross-sectional area of ​​the outlet 38a of the first flow path 38 is smaller than the flow path cross-sectional area of ​​the outlet 33a of the supply port 33. Furthermore, the width H1 of the second flow path 39 is set to be at least twice the width H2 of the outlet 38a of the first flow path 38. Therefore, the flow path cross-sectional area of ​​the second flow path 39 is at least twice the flow path cross-sectional area of ​​the outlet 38a of the first flow path 38. Furthermore, the width H1 of the second flow path 39 is set to be at least twice the width H3 of the inlet 40a of the third flow path 40. Therefore, the flow path cross-sectional area of ​​the second flow path 39 is at least twice the flow path cross-sectional area of ​​the inlet 40a of the third flow path 40. The flow path cross-sectional area of ​​the inlet 35a of the inlet 35 is the same as the flow path cross-sectional area of ​​the outlet 36. The flow path cross-sectional area of ​​the outlet 38a of the first flow path 38 is the same as the flow path cross-sectional area of ​​the inlet 35a of the inlet 35 and the flow path cross-sectional area of ​​the outlet 36.

[0044] After the cooling fluid flowing in from the outside is introduced into the inverter cooling flow path 31, it branches at the inlet 35 into a fluid flow flowing in the inverter cooling flow path 31 and a fluid flow flowing in the motor cooling flow path 32. The branched cooling fluids merge at the outlet 36 and are discharged to the outside through the inverter cooling flow path 31.

[0045] Next, the operation of this embodiment will be described.

[0046] exist Figure 5 In FIG, the inverter cooling flow path 31 and the motor cooling flow path 32 are expanded and schematically shown. Figure 5 As shown, the cooling fluid supplied from the supply port 33 to the inverter cooling flow path 31 flows into the first flow path 38. The cooling fluid flowing in the first flow path 38 is divided into the cooling fluid that flows through the communication flow path 37 toward the second flow path 39 and the cooling fluid that flows into the motor cooling flow path 32 via the inlet 35. Therefore, a portion of the cooling fluid flowing in the inverter cooling flow path 31 branches off from the inlet 35 and flows into the motor cooling flow path 32.

[0047] The cooling fluid flowing from the first flow path 38 to the second flow path 39 in the communication flow path 37 is as follows: Figure 5 As indicated by the middle arrow A1, the cooling fluid flows through the second flow path 39 and flows into the third flow path 40, flows through the third flow path 40, and is discharged to the outside through the discharge port 34. It should be noted that a portion of the cooling fluid flowing in the third flow path 40 flows into the inlet 41, flows into the motor cooling flow path 32, flows out of the outlet 42 into the third flow path 40, and is discharged to the outside through the discharge port 34.

[0048] On the other hand, Figure 5 As shown by the arrow A2 in the middle, the cooling fluid flows from the first flow path 38 through the inlet 35 into the motor cooling flow path 32. Figure 5 As shown by the arrow A3 in the middle, the cooling fluid passes through the motor cooling flow path 32 and flows out to the second flow path 39 of the inverter cooling flow path 31 through the outflow port 36. Therefore, the cooling fluid flowing in the motor cooling flow path 32 merges with the inverter cooling flow path 31 at the outflow port 36. At this time, when viewed from the axial direction of the rotating shaft 16, the width H1 of the second flow path 39 is wider than the width H2 of the first flow path 38. When viewed from the axial direction of the rotating shaft 16, the outflow port 36 falls within the projected area of ​​the second flow path 39. In this way, due to the expansion of the flow path, the second flow path 39 is expanded as shown in FIG. Figure 5 As indicated by arrow A4, a vortex of the cooling fluid is generated, resulting in slight pressure loss. Consequently, compared to, for example, a case where the width H1 of the second flow path 39 is less than the width H2 of the first flow path 38, the cooling fluid flowing in the motor cooling flow path 32 is more likely to flow out of the second flow path 39 through the outflow port 36. Consequently, the cooling fluid flows more easily in the motor cooling flow path 32, thereby minimizing any reduction in cooling efficiency caused by the cooling fluid flowing in the motor cooling flow path 32.

[0049] Furthermore, the cooling fluid flowing out from the motor cooling flow path 32 through the outflow port 36 to the second flow path 39 of the inverter cooling flow path 31 is as follows: Figure 5As indicated by arrow A5 , the fluid flows toward the third flow path 40 while following the vortex of the cooling fluid and the flow of the cooling fluid flowing from the first flow path 38 into the second flow path, flows through the third flow path 40 , and is discharged to the outside from the discharge port 34 .

[0050] Heat generated by the inverter 28 is transferred to the flow path-forming housing 14 and dissipated by the cooling fluid flowing through the inverter cooling flow path 31. Therefore, the cooling fluid flowing through the inverter cooling flow path 31 cools the inverter 28. Furthermore, heat generated by the electric motor 17 is transferred to the peripheral wall 13b of the motor housing 13 and dissipated by the cooling fluid flowing through the motor cooling flow path 32. Therefore, the cooling fluid flowing through the motor cooling flow path 32 cools the electric motor 17.

[0051] In the above-described embodiment, the following effects can be obtained.

[0052] (1) The inverter 28 is cooled using the cooling fluid flowing through the inverter cooling flow path 31. Furthermore, a portion of the cooling fluid flowing through the inverter cooling flow path 31 branches off from the inlet 35 and flows through the motor cooling flow path 32. Furthermore, the cooling fluid flowing through the motor cooling flow path 32 merges with the inverter cooling flow path 31 at the outlet 36. In this case, the inverter cooling flow path 31 includes a second flow path 39 that generates a vortex, and the outlet 36 is provided in the second flow path 39. This generates a vortex within the inverter cooling flow path 31, causing slight pressure loss. Therefore, compared to a case where no vortex is generated, for example, the cooling fluid flowing through the motor cooling flow path 32 is more likely to merge with the second flow path 39 through the outlet 36. Therefore, the cooling fluid flows more easily through the motor cooling flow path 32. As a result, it is possible to suppress a decrease in cooling efficiency caused by the cooling fluid flowing through the cooling flow path 30.

[0053] (2) The inlet 35 and outlet 36 are provided at the boundary between the end wall 13a and the peripheral wall 13b, which are part of the partition 50 in the housing 11. This structure is preferred as it facilitates the formation of a cooling flow path 30 with excellent cooling performance. Furthermore, in this structure, the motor cooling flow path 32 branches and merges perpendicularly with the inverter cooling flow path 31, which can easily cause a backflow of the cooling fluid at the merging point. Accordingly, the provision of the second flow path 39 provides a greater benefit.

[0054] (3) A configuration in which the flow path cross-sectional area of ​​the second flow path 39 is twice or more the flow path cross-sectional area of ​​the first flow path 38 is preferable as a configuration in which the cooling fluid flowing in the motor cooling flow path 32 easily flows out to the second flow path 39 through the outflow port 36 .

[0055] (4) When viewed from the axial direction of the rotating shaft 16, the width of the second flow path 39 expands in a direction away from the inlet 40a of the third flow path 40, and the outflow port 36 communicates with the second flow path 39 at a position away from the third flow path 40. As a result, the cooling fluid flowing in the motor cooling flow path 32 easily flows out of the second flow path 39 through the outflow port 36. Therefore, the cooling fluid easily flows in the motor cooling flow path 32, and the pressure loss of the cooling fluid flowing in the motor cooling flow path 32 can be suppressed.

[0056] It should be noted that the above embodiment can be implemented by modifications as follows: The above embodiment and the following modifications can be implemented in combination with each other within the scope of no technical contradiction.

[0057] In the embodiment, as long as the flow path cross-sectional area of ​​the second flow path 39 is larger than the flow path cross-sectional area of ​​the first flow path 38 , the flow path cross-sectional area of ​​the second flow path 39 may be smaller than twice the flow path cross-sectional area of ​​the first flow path 38 .

[0058] In the embodiment, the inverter cooling flow path 31 has a U-shape when viewed from the axial direction of the rotating shaft, but the shape of the inverter cooling flow path 31 is not particularly limited.

[0059] In the embodiment, the electric compressor 10 may also be configured such that the inverter cooling flow path 31 is formed in the end wall 13a of the motor housing 13. In this case, the electric compressor 10 can be configured such that the flow path-forming housing 14 is omitted. In short, the inverter cooling flow path 31 may be formed in the partition 50 that separates the motor chamber 18 from the inverter chamber 29 in the axial direction of the rotating shaft 16.

[0060] In the embodiment, the compression unit 25 is not limited to the scroll type, and may be, for example, a piston type, a vane type, or the like.

[0061] In the embodiment, the fluid machine is used as the electric compressor 10 in the vehicle air conditioner 27, but the present invention is not limited to this. For example, the fluid machine may be installed in a fuel cell vehicle as an electric compressor, where the compressor portion compresses air as the fluid supplied to the fuel cell, or may be used as an electric pump, where the pump portion pressurizes and delivers hydrogen as the fluid supplied to the fuel cell.

Claims

1. A fluid machine comprising: Rotation axis; an electric motor that rotates the rotating shaft; a pump unit configured to pressurize and deliver a fluid by the rotation of the rotary shaft; an inverter that drives the electric motor; and a housing having a motor chamber for accommodating the electric motor and an inverter chamber for accommodating the inverter, The motor chamber and the inverter chamber are arranged side by side in the axial direction of the rotating shaft. The housing is provided with a cooling passage through which a cooling fluid for cooling the electric motor and the inverter flows. The housing includes: a plate-shaped partition portion that partitions the motor chamber and the inverter chamber in the axial direction of the rotating shaft; and a peripheral wall portion that extends cylindrically from the partition portion in the axial direction of the rotating shaft and surrounds the electric motor. The fluid machinery is characterized in that The cooling flow path has: an inverter cooling flow path for allowing a cooling fluid to flow inside the partition; and a motor cooling flow path for cooling fluid to flow inside the peripheral wall portion; One end of the motor cooling flow path is connected to the inverter cooling flow path at the inlet branch portion of the housing, so that the motor cooling flow path branches off from the inverter cooling flow path, and the other end of the motor cooling flow path is connected to the inverter cooling flow path at the outlet branch portion of the housing, so that the motor cooling flow path and the inverter cooling flow path merge. After being introduced into the inverter cooling flow path, the cooling fluid branches at the inlet branch portion into a fluid flow flowing in the inverter cooling flow path and a fluid flow flowing in the motor cooling flow path. The fluid flow flowing in the inverter cooling flow path and the fluid flow flowing in the motor cooling flow path merge at the outlet branch portion and are discharged from the inverter cooling flow path. The inverter cooling flow path includes a flow path expansion portion that generates eddy current. The outlet branch portion is provided at the flow path expansion portion.

2. The fluid machinery according to claim 1, characterized in that: The inverter cooling flow path extends inside the partition in a direction perpendicular to the rotation axis. The motor cooling flow path extends inside the peripheral wall portion along the axial direction of the rotating shaft. The inlet branch portion and the outlet branch portion are provided at the boundary between the partition portion and the peripheral wall portion in the housing.

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