Turbo Fluid Machinery

Abstract

To provide a turbo type fluid machine which can achieve reduction of the size and manufacturing costs while preferably preventing leakage of a fluid from an impeller chamber to the outside of a housing.SOLUTION: In a turbo type fluid machine of the invention, a housing 1 has first to fourth housings 11 to 14. A first gasket 31 is provided between the first housing 11 and the second housing 12. A second gasket 32 is provided between the second housing 12 and the third housing 13. A third gasket 33 is provided between the third housing 13 and the fourth housing 14. The first housing 11 and the second housing 12 contact with each other at the outer periphery side of the first gasket 31. The second housing 12 and the third housing 13 contact with each other at the outer periphery side of the second gasket 32. The third housing 13 and the fourth housing 14 contact with each other at the outer periphery side of the third gasket 33.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a turbo fluid machine. [Background technology]

[0002] Patent Document 1 discloses a conventional turbo fluid machine. This turbo fluid machine includes a housing, an impeller, and a drive shaft. The housing defines an impeller chamber and a motor chamber. An electric motor is accommodated in the motor chamber. The impeller is accommodated in the impeller chamber. The impeller compresses fluid by rotation of the electric motor. The drive shaft is accommodated in the housing. The drive shaft extends in the axial direction and connects the impeller and the electric motor. In this document, the fluid is specifically a refrigerant.

[0003] The housing includes a first housing and a second housing, which are arranged in the axial direction of the drive shaft, so that the first housing and the second housing form an impeller chamber therebetween.

[0004] An O-ring is provided between the first housing and the second housing. More specifically, the O-ring is provided at a location on the inner periphery of the first housing and on the outer periphery of the second housing in the radial direction of the housing.

[0005] In this turbo fluid machine, the O-ring is sandwiched between the first housing and the second housing and elastically deforms in the radial direction, thereby sealing the space between the impeller chamber and the outside of the housing while abutting against the first housing and the second housing. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2009-281277 A Summary of the Invention [Problem to be solved by the invention]

[0007] In this type of turbo fluid machine, miniaturization is required to improve mountability in vehicles, etc., while preventing high-pressure fluid in the impeller chamber from leaking out of the housing. However, in the above-mentioned conventional turbo fluid machine, a space is required to place an O-ring between the first housing and the second housing in the radial direction of the housing. Therefore, it is difficult to reduce the radial size of this turbo fluid machine, and therefore it is difficult to further reduce the size.

[0008] Therefore, it is conceivable to provide a gasket between the first housing and the second housing instead of the O-ring. However, in order to provide a suitable seal between the impeller chamber and the outside of the housing with the gasket, it is necessary to provide a suitable clearance between the first housing and the second housing for providing the gasket. This makes it difficult to manufacture such a turbo fluid machine, and increases the manufacturing costs.

[0009] The present invention has been made in consideration of the above-mentioned conventional situation, and has as its object to provide a turbo-type fluid machine that can be made compact and have low manufacturing costs while effectively preventing leakage of fluid from within the impeller chamber to the outside of the housing. [Means for solving the problem]

[0010] The turbo fluid machine of the present invention includes a housing in which an impeller chamber and a motor chamber for accommodating an electric motor are formed, an impeller housed in the impeller chamber and compressing a fluid by rotation of the electric motor; a drive shaft accommodated in the housing, extending in an axial direction and connecting the impeller and the electric motor; A metal seal is provided between the impeller chamber and the outside of the housing. Formed by planks and a gasket. The housing includes a first housing and a second housing that defines the impeller chamber together with the first housing. The first housing and the second housing are arranged in the axial direction, The gasket is provided between the first housing and the second housing in the axial direction, the first housing has an end surface facing the second housing in the axial direction, the second housing has an end face facing an end face of the first housing in the axial direction, an end surface of the first housing has a first main body portion that abuts against the gasket in the axial direction and a first outer circumferential portion that is located on an outer periphery of the gasket and the first main body portion; an end surface of the second housing has a second main body portion that abuts against the gasket in the axial direction and sandwiches the gasket between the second main body portion and the first main body portion, and a second outer circumferential portion that is located on an outer periphery of the gasket and the second main body portion, The first Outer periphery and the second Outer periphery The outer circumferential side of the gasket and directly contacts the gasket, the first body portion, and the second body portion in the axial direction at a position spaced apart from the gasket, the first body portion, and the second body portion in the axial direction; The first main body portion, the second main body portion, the first outer circumferential portion, and the second outer circumferential portion form a boundary portion between an end face of the first housing and an end face of the second housing in a stepped shape that is bent in the axial direction. It is characterized by:

[0011] In the turbo fluid machine of the present invention, a gasket is provided between the first housing and the second housing in the axial direction, and the gasket seals the impeller chamber and the outside of the housing. Therefore, the housing can be made smaller in the radial direction than when an O-ring seals the impeller chamber and the outside of the housing.

[0012] In addition, since the gasket in this turbo fluid machine is made of metal, the gasket has sufficient rigidity to withstand the pressure of the fluid in the impeller chamber. Therefore, the gasket can adequately seal between the impeller chamber and the outside of the housing. In addition, since the gasket is made of metal, the cost of the gasket itself can be reduced, and the gasket can be easily assembled to the housing.

[0013] In this turbo fluid machine, the first Outer periphery and the second Outer periphery The outer periphery of the gasket At a position axially spaced apart from the gasket, the first body portion, and the second body portion, As a result, in this turbo fluid machine, a clearance for providing a gasket can be suitably secured.

[0014] Therefore, according to the turbo fluid machine of the present invention, it is possible to effectively prevent leakage of fluid from within the impeller chamber to the outside of the housing, while achieving miniaturization and low manufacturing costs.

[0016] Also, The turbo fluid machine of the present invention includes a housing in which an impeller chamber and a motor chamber for accommodating an electric motor are formed, an impeller housed in the impeller chamber and compressing a fluid by rotation of the electric motor; a drive shaft accommodated in the housing, extending in an axial direction and connecting the impeller and the electric motor; a metal gasket for sealing between the impeller chamber and the outside of the housing, The housing includes a first housing and a second housing that defines the impeller chamber together with the first housing. The first housing and the second housing are arranged in the axial direction, The gasket is provided between the first housing and the second housing in the axial direction, The first housing and the second housing are in contact with each other in the axial direction only on the inner circumferential side of the gasket.

[0017] child As a result This facilitates assembly of the housing and the gasket, and ultimately facilitates manufacture of the turbo fluid machine, compared to when the first housing and the second housing abut on both the outer and inner sides of the gasket.

[0018] In this turbo fluid machine, It is preferable that the first housing and the second housing abut against each other at a position spaced apart in the axial direction from the gasket. First Housing and Second Housing and can be preferably brought into contact with each other.

[0019] The impeller chamber may have a first impeller chamber formed by the first housing and the second housing, and a second impeller chamber located between the first impeller chamber and the motor chamber in the axial direction and communicating with the first impeller chamber. The housing may have a third housing forming the second impeller chamber together with the second housing. The second housing and the third housing may be arranged in the axial direction. The gasket may have a first gasket provided between the first housing and the second housing in the axial direction and sealing between the first impeller chamber and the outside of the housing, and a second gasket provided between the second housing and the third housing in the axial direction and sealing between the second impeller chamber and the outside of the housing. It is preferable that the second housing and the third housing abut in the axial direction at least on one of the outer circumferential side and the inner circumferential side of the second gasket.

[0020] In this case, the first gasket can provide a suitable seal between the first impeller chamber and the outside of the housing. Also, the second gasket can provide a suitable seal between the second impeller chamber and the outside of the housing. And, since the second housing and the third housing are in axial contact with each other on at least one of the outer circumferential side and the inner circumferential side of the second gasket, a clearance for providing the second gasket can be provided suitably.

[0021] In this case, it is preferable that the first and second housings, and the second and third housings are in contact only on the outer circumferential side or the inner circumferential side of the first and second gaskets.

[0022] This makes it possible to facilitate the manufacture of the turbo fluid machine even though it has the first to third housings and the first and second gaskets.

[0023] The housing may also have a fourth housing forming a motor chamber together with the third housing. The third housing and the fourth housing may be arranged in the axial direction. The gasket may further have a third gasket provided between the third housing and the fourth housing in the axial direction and sealing between the second impeller chamber and the motor chamber and the outside of the housing. It is preferable that the third housing and the fourth housing abut in the axial direction at least on one of the outer circumferential side and the inner circumferential side of the third gasket.

[0024] In this case, the third gasket can suitably seal between the second impeller chamber and the motor chamber and between the outside of the housing. In addition, since the third housing and the fourth housing are in axial contact with each other on at least one of the outer circumferential side and the inner circumferential side of the third gasket, a clearance for providing the third gasket can be suitably secured. Effect of the Invention

[0025] According to the turbo fluid machine of the present invention, it is possible to effectively prevent leakage of fluid from within the impeller chamber to the outside of the housing, while realizing miniaturization and low manufacturing costs. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 is a cross-sectional view showing a turbo fluid machine according to a first embodiment. [Diagram 2] FIG. 2 is an enlarged cross-sectional view of a main part of the turbo fluid machine of the first embodiment, showing a portion X1 in FIG. [Diagram 3] FIG. 3 is a front view showing a third housing, a second gasket, and the like in the turbo fluid machine of the first embodiment. [Figure 4] FIG. 4 is a front view showing the fourth housing, the third gasket, and the like in the turbo fluid machine of the first embodiment. [Diagram 5] FIG. 5 is a front view of the turbo fluid machine according to the first embodiment, showing abutment points of the third housing with the second housing, and the like. [Figure 6] FIG. 6 is a front view showing a contact portion between the fourth housing and the third housing and the like in the turbo fluid machine of the first embodiment. [Figure 7] Second Embodiment FIG. 7 is an enlarged cross-sectional view of a main portion of a turbo fluid machine according to a second embodiment, similar to FIG. [Figure 8] FIG. 8 is a front view similar to FIG. 5, showing a turbo fluid machine according to a second embodiment. [Figure 9] FIG. 9 is a front view similar to FIG. 6, showing a turbo fluid machine according to a second embodiment. [Figure 10] FIG. 10 is a front view similar to FIG. 5, showing a turbo fluid machine of a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Hereinafter, first and second embodiments and a modification of the present invention will be described with reference to the drawings. The turbo fluid machines of the first and second embodiments and the modification are mounted on a vehicle (not shown) and used in a refrigeration cycle of an air conditioner for the vehicle.

[0028] Example 1 1, the turbo fluid machine of the first embodiment includes a housing 1, an electric motor 3, a first impeller 5, a second impeller 7, a drive shaft 9, and first to third gaskets 31 to 33. The housing 1 has a first housing 11, a second housing 12, a third housing 13, and a fourth housing 14.

[0029] In this embodiment, the front-rear direction and the up-down direction of the turbo fluid machine are defined by solid arrows shown in Fig. 1. This front-rear direction is an example of the "axial direction of the drive shaft" in the present invention. In Fig. 2 and subsequent figures, the front-rear direction and the up-down direction of the turbo fluid machine are defined in accordance with Fig. 1. The turbo fluid machine can change its own attitude as appropriate depending on the vehicle in which it is mounted.

[0030] The housing 1, i.e., the first to fourth housings 11 to 14, are made of metal such as an aluminum alloy. The first housing 11, the second housing 12, the third housing 13, and the fourth housing 14 are aligned in the stated order in the front-to-rear direction. As a result, the first housing 11 forms the front part of the housing 1, and the fourth housing 14 forms the rear part of the housing 1.

[0031] The fourth housing 14 is composed of a first block 61, a second block 62, and a third block 63. The first block 61, the second block 62, and the third block 63 are aligned in this order in the front-rear direction. As a result, the first block 61 is located at the frontmost position in the fourth housing 14.

[0032] The first housing 11 has a first front end surface 11a and a first rear end surface 11b. The first front end surface 11a is located at the front end of the first housing 11. As a result, the first front end surface 11a constitutes the front end surface of the housing 1. The first rear end surface 11b is located at the rear end of the first housing 11.

[0033] Similarly, the second housing 12 has a second front end face 12a and a second rear end face 12b, and the third housing 13 has a third front end face 13a and a third rear end face 13b. The second and third front end faces 12a and 13a are located at the front ends of the second and third housings 12 and 13, respectively. Meanwhile, the second and third rear end faces 12b and 13b are located at the rear ends of the second and third housings 12 and 13, respectively.

[0034] In the fourth housing 14, the first block 61 has a fourth front end face 14a and a fourth rear end face 14b, the second block 62 has a fifth front end face 14c and a fifth rear end face 14d, and the third block 63 has a sixth front end face 14e and a sixth rear end face 14f. The fourth to sixth front end faces 14a, 14c, and 14e are located at the front ends of the first to third blocks 61 to 63, respectively. Meanwhile, the fourth to sixth rear end faces 14b, 14d, and 14f are located at the rear ends of the first to third blocks 61 to 63, respectively. That is, the fourth front end face 14a constitutes the front end face of the fourth housing 14, and the sixth rear end face 14f constitutes the rear end face of the fourth housing 14.

[0035] 2, the second housing 12 is disposed behind the first housing 11, so that the first rear end surface 11b and the second front end surface 12a face each other in the front-rear direction. As shown in FIG 1, the first housing 11 and the second housing 12 form a first impeller chamber 15 therebetween.

[0036] 2, the third housing 13 is disposed behind the second housing 12, so that the second rear end surface 12b and the third front end surface 13a face each other in the front-rear direction. As shown in FIG 1, the second housing 12 and the third housing 13 form a second impeller chamber 17 therebetween. The first block 61 is disposed behind the third housing 13, so that the third rear end surface 13b and the fourth front end surface 14a face each other in the front-rear direction.

[0037] 2, the boundary between the first housing 11 and the second housing 12, i.e., the boundary between the first rear end face 11b and the second front end face 12a, is defined as a first divided portion 21. The boundary between the second housing 12 and the third housing 13, i.e., the boundary between the second rear end face 12b and the third front end face 13a, is defined as a second divided portion 22.

[0038] The boundary portion between the third housing 13 and the first block 61, that is, the boundary portion between the third rear end face 13b and the fourth front end face 14a, is defined as a third divided portion .

[0039] Of the first to third divided portions 21 to 23, the first divided portion 21 is located furthest forward, and the third divided portion 23 is located furthest rearward. The second divided portion 22 is disposed between the first divided portion 21 and the third divided portion 23 in the front-rear direction. As a result, the first rear end face 11b is located forward of the first divided portion 21, and the second front end face 12a is located rearward of the first divided portion 21. The second rear end face 12b is located forward of the second divided portion 22, and the third front end face 13a is located rearward of the second divided portion 22. The third rear end face 13b is located forward of the third divided portion 23, and the fourth front end face 14a is located rearward of the third divided portion 23.

[0040] Moreover, a first gasket 31 is provided in the first divided portion 21, a second gasket 32 ​​is provided in the second divided portion 22, and a third gasket 33 is provided in the third divided portion 23. The first to third gaskets 31 to 33 will be described in detail later.

[0041] Here, the first rear end surface 11b has a first rear main body portion 111 facing the first gasket 31, and a first rear outer periphery portion 112 located on the outer periphery of the first rear main body portion 111. In the first rear main body portion 111, a front portion of the first impeller chamber 15 is formed.

[0042] Further, the second front end surface 12a has a second front main body portion 121 facing the first gasket 31 and a second front outer periphery portion 122 located on the outer periphery of the second front main body portion 121. The rear portion of the first impeller chamber 15 is formed in the second front main body portion 121. The second rear end surface 12b has a second rear main body portion 123 facing the second gasket 32 ​​and a second rear outer periphery portion 124 located on the outer periphery of the second rear main body portion 123. The front portion of the second impeller chamber 17 is formed in the second rear main body portion 123.

[0043] 3, the third front end surface 13a has a third front main body portion 131 facing the second gasket 32, and a third front outer periphery portion 132 located on the outer periphery of the third front main body portion 131. In addition to forming a rear portion of the second impeller chamber 17, the third front main body portion 131 is also formed with a first positioning protrusion 131a and a second positioning protrusion 131b. The first positioning protrusion 131a and the second positioning protrusion 131b protrude forward from the third front main body portion 131 in a substantially hemispherical shape.

[0044] As shown in FIG. 2, the third rear end surface 13b has a third rear main body portion 133 facing the third gasket 33, and a third rear outer periphery portion 134 located on the outer periphery of the third rear main body portion 133.

[0045] As shown in Fig. 4, the fourth front end surface 14a has a fourth front body portion 141 facing the third gasket 33, and a fourth front outer periphery portion 142 located on the outer periphery of the fourth front body portion 141. A third positioning protrusion 141a and a fourth positioning protrusion 141b are formed on the fourth front body portion 141. The third positioning protrusion 141a and the fourth positioning protrusion 141b protrude forward from the fourth front body portion 141 in a substantially hemispherical shape. The shapes and numbers of the third and fourth positioning protrusions 141a and 141b can be designed as appropriate. The same applies to the first and second positioning protrusions 131a and 131b.

[0046] 2, the first rear outer circumferential portion 112, the second rear outer circumferential portion 124, and the third rear outer circumferential portion 134 are formed to be recessed forward with respect to the first rear main body portion 111, the second rear main body portion 123, and the third rear main body portion 133, respectively. On the other hand, the second front outer circumferential portion 122, the third front outer circumferential portion 132, and the fourth front outer circumferential portion 142 are formed to protrude forward more than the second front main body portion 121, the third front main body portion 131, and the fourth front main body portion 141. As a result, the first to third divided portions 21 to 23 do not extend flat in the radial direction of the housing 1, but have a stepped shape with the outer circumferential side bent forward.

[0047] The first to fourth housings 11 to 14 are fastened in the front-rear direction by first to fourth fastening bolts 19a to 19d (see Figs. 5 and 6) with the electric motor 3, drive shaft 9, first impeller 5, second impeller 7, etc., disposed therein and the first to third gaskets 31 to 33 disposed in the first to third divided parts 21 to 23, respectively. As a result, the first to fourth housings 11 to 14 and the first to third gaskets 31 to 33 are integrally assembled as shown in Fig. 1. Note that, for ease of explanation, the fastening bolts 19a to 19d are omitted in Figs. 1 and 2. The same applies to Fig. 7, which will be described later.

[0048] By assembling in this manner with the fastening bolts 19a to 19d, a front portion of the first impeller chamber 15 formed in the first rear body portion 111 and a rear portion of the first impeller chamber 15 formed in the second front body portion 121 are joined in the front-rear direction. Also, a front portion of the second impeller chamber 17 formed in the second rear body portion 123 and a rear portion of the second impeller chamber 17 formed in the third front body portion 131 are joined in the front-rear direction. In this manner, as shown in FIG. 1, the first housing 11 and the second housing 12 form the first impeller chamber 15 therein. And the second housing 12 and the third housing 13 form the second impeller chamber 17 therein.

[0049] A second suction port 25 is formed in the first housing 11. The second suction port 25 is located in the center of the first housing 11 and extends in the front-rear direction within the first housing 11. The rear end of the second suction port 25 is connected to the first impeller chamber 15. The front end of the second suction port 25 communicates with the outside of the first housing 11, i.e., the outside of the housing 1. Although not shown, the first housing 11 is formed with a second discharge port that communicates between the first impeller chamber 15 and the outside of the housing 1.

[0050] A first shaft hole 27 is formed in the second housing 12. The first shaft hole 27 is located in the center of the second housing 12. The first shaft hole 27 is coaxial with the second suction port 25 and extends in the front-rear direction within the second housing 12. The front end of the first shaft hole 27 is connected to the first impeller chamber 15, and the rear end is connected to the second impeller chamber 17.

[0051] A second shaft hole 37 is formed in the third housing 13. The second shaft hole 37 is located in the center of the third housing 13. The second shaft hole 37 is coaxial with the second suction port 25 and the first shaft hole 27, and extends in the front-rear direction within the third housing 13. The second shaft hole 37 is formed to have a larger diameter than the first shaft hole 27, and its front end is connected to the second impeller chamber 17. On the other hand, the rear end of the second shaft hole 37 opens to the rear end of the third housing 13.

[0052] 3 and 5, the third housing 13 is formed with an insertion hole 43a through which the first fastening bolt 19a is inserted, an insertion hole 43b through which the second fastening bolt 19b is inserted, an insertion hole 43c through which the third fastening bolt 19c is inserted, and an insertion hole 43d through which the fourth fastening bolt 19d is inserted. Each of the insertion holes 43a to 43d extends from the third front end face 13a to the third rear end face 13b, more specifically, from the third front outer periphery 132 to the third rear outer periphery 134.

[0053] 1, a first discharge port 29 is formed in the third housing 13, which connects the second impeller chamber 17 with the outside of the housing 1. The first discharge port 29 is connected to the second suction port 25 via a pipe 200.

[0054] The first block 61 has a first bottom wall 61a and a first peripheral wall 61b. The first bottom wall 61a is located at the rear end of the first block 61 and extends in the radial direction. A third shaft hole 38 is formed in the center of the first bottom wall 61a. The third shaft hole 38 is coaxial with the second shaft hole 37 and penetrates the first bottom wall 61a in the front-rear direction. A first communication hole 40a and a second communication hole 40b are formed in the first bottom wall 61a. The first communication hole 40a and the second communication hole 40b are formed with a smaller diameter than the third shaft hole 38 and each penetrates the first bottom wall 61a in the front-rear direction.

[0055] The first peripheral wall 61b is connected to the outer periphery of the first bottom wall 61a and extends forward from the first bottom wall 61a.

[0056] The first block 61 has a cylindrical shape with a bottom that extends in the front-rear direction by the first bottom wall 61a and the first peripheral wall 61b. The first block 61 forms a first motor chamber 140a between itself and the third housing 23. The first motor chamber 140a communicates with the second shaft hole 37.

[0057] The second block 62 has a second bottom wall 62a and a second peripheral wall 62b. The second bottom wall 62a is located at the rear end of the second block 62 and extends in the radial direction. A fourth shaft hole 39 is formed in the center of the second bottom wall 62a. The fourth shaft hole 39 is coaxial with the third shaft hole 38 and penetrates the second bottom wall 62a in the front-rear direction.

[0058] Furthermore, the second bottom wall 62a is formed with a third communication hole 40c and a fourth communication hole 40d, as well as a first housing portion 44. The third communication hole 40c and the fourth communication hole 40d are formed with a smaller diameter than the fourth shaft hole 39, and each penetrates the second bottom wall 62a in the front-rear direction. The first housing portion 44 is located at the center of the second bottom wall 62a and is recessed forward from the rear end of the second bottom wall 62a. The first housing portion 44 has a larger diameter than the fourth shaft hole 39, and is connected to the fourth shaft hole 39. A first radial bearing 51 is provided in the first housing portion 44.

[0059] The second peripheral wall 62b is connected to the outer periphery of the second bottom wall 62a and extends forward from the second bottom wall 62a.

[0060] The second block 62 has a bottomed cylindrical shape extending in the front-rear direction by the second bottom wall 62a and the second peripheral wall 62b. The second block 62 forms a second motor chamber 140b between itself and the first block 61. The first thrust bearing 52 and the second thrust bearing 53 are provided in the second motor chamber 140b.

[0061] The third block 63 has a third bottom wall 63a and a third peripheral wall 63b. The third bottom wall 63a is located at the rear end of the third block 63, and therefore at the rear end of the fourth housing 14, and extends in the radial direction. The third bottom wall 63a has a second housing portion 45 formed therein. The second housing portion 45 is located at the center of the third bottom wall 63a. The second housing portion 45 is recessed rearward from the front end of the third bottom wall 63a, while being coaxial with the third shaft hole 38 and the fourth shaft hole 39. The second housing portion 45 is provided in the second housing portion 45.

[0062] The third peripheral wall 63b is connected to the outer periphery of the third bottom wall 63a and extends forward from the third bottom wall 63a. The third peripheral wall 63b is formed with a first suction port 41. The first suction port 41 penetrates the third peripheral wall 63b in the radial direction.

[0063] The third block 63 has a bottomed cylindrical shape extending in the front-rear direction by the third bottom wall 63a and the third peripheral wall 63b. The third block 63 and the second block 62 form a third motor chamber 140c.

[0064] The first to third motor chambers 140a to 140c are in communication with one another through the first to fourth communication holes 40a to 40d. As a result, the first to third motor chambers 140a to 140c form a motor chamber 140. The motor chamber 140 is in communication with the second shaft hole 37 through the first motor chamber 140a.

[0065] Moreover, the motor chamber 140, more specifically, the third motor chamber 140c, is in communication with the outside of the housing 1 through the first suction port 41. As a result, refrigerant gas is drawn into the motor chamber 140 from the outside of the housing 1 through the first suction port 41. The refrigerant gas is an example of the "fluid" in the present invention.

[0066] 4 and 6, the fourth housing 14, i.e., the first to third blocks 61 to 63, are provided with an insertion hole 49a through which the first fastening bolt 19a is inserted, an insertion hole 49b through which the second fastening bolt 19b is inserted, an insertion hole 49c through which the third fastening bolt 19c is inserted, and an insertion hole 49d through which the fourth fastening bolt 19d is inserted. The insertion holes 49a to 49d are connected to the insertion holes 43a to 43d of the third housing 13, respectively, and extend from the fourth front outer periphery 142 of the fourth front end face 14a into the fourth housing 14. Although not shown, the first housing 11 and the second housing 12 are also provided with insertion holes through which the first to fourth fastening bolts 19a to 19d are inserted, respectively.

[0067] As shown in FIG. 1, the electric motor 3 is housed in the motor chamber 140, more specifically, in the third motor chamber 140c. The electric motor 3 has a stator 3a and a rotor 3b. The stator 3a is formed in a cylindrical shape extending in the front-rear direction, and is fixed to the inner wall of the fourth housing 14. The stator 3a is connected to a power supply device (not shown) provided outside the housing 1. The rotor 3b is formed in a cylindrical shape extending in the front-rear direction with a smaller diameter than the stator 3a. The rotor 3b is disposed within the stator 3a.

[0068] Further, the first radial bearing 51 accommodated in the first accommodating portion 44 is located further forward in the motor chamber 140 than the stator 3a, and hence the electric motor 3.

[0069] The first impeller 5 is housed in the first impeller chamber 15. The first impeller 5 is formed in a generally conical shape that gradually increases in diameter from the front to the rear. The second impeller 7 is located behind the first impeller 5, and is housed in the second impeller chamber 17. The second impeller 7 has a shape symmetrical to the first impeller 5 in the front-rear direction. In other words, the second impeller 7 is formed in a generally conical shape that gradually decreases in diameter from the front to the rear.

[0070] The drive shaft 9 is formed in a cylindrical shape extending in the front-rear direction, and is disposed within the first to fourth housings 11 to 14, i.e., within the housing 1. The drive shaft 9 is composed of a small diameter section 9a and a large diameter section 9b. The small diameter section 9a constitutes the front portion of the drive shaft 9, and enters the second intake port 25 of the first housing 11, the first shaft hole 27 of the second housing 12, the second shaft hole 37 of the third housing 13, and the first motor chamber 140a.

[0071] The small diameter portion 9a is formed to have a smaller diameter than any of the second suction port 25, the first shaft hole 27, and the second shaft hole 37. The small diameter portion 9a is press-fitted into the inside of the first impeller 5 and the inside of the second impeller 7. As a result, the small diameter portion 9a is fixed to the first impeller 5 and the second impeller 7.

[0072] The large diameter portion 9b is connected to the rear end of the small diameter portion 9a and extends rearward. As a result, the large diameter portion 9b constitutes the rear portion of the drive shaft 9. The large diameter portion 9b is press-fitted into the rotor 3b and fixed to the rotor 3b. In this way, the drive shaft 9 connects the first impeller 5, the second impeller 7, and the electric motor 3.

[0073] The front side of the large diameter portion 9b enters the third shaft hole 38, the fourth shaft hole 39, and the first housing portion 44, and is rotatably supported by the first radial bearing 51. On the other hand, the rear side of the large diameter portion 9b enters the second housing portion 45, and is rotatably supported by the second radial bearing 54.

[0074] Furthermore, the large diameter portion 9b is inserted through the first thrust bearing 52 and the second thrust bearing 53 in the second motor chamber 140b. A support plate 91 is press-fitted into the large diameter portion 9b. The support plate 91 is disposed in the second motor chamber 140b and is located between the first thrust bearing 52 and the second thrust bearing 53. As a result, the support plate 91 holds the first thrust bearing 52 between itself and the first bottom wall 61a of the first block 61, and holds the second thrust bearing 53 between itself and the second bottom wall 62a of the second block 62. In this way, the first thrust bearing 52 and the second thrust bearing 53 are capable of supporting the thrust load acting on the drive shaft 9.

[0075] The drive shaft 9 can be rotated by the electric motor 3. More specifically, the drive shaft 9 has its own axis as a drive axis O and can rotate around this drive axis O. As the drive shaft 9 rotates around the drive axis O, the first impeller 5 rotates around the drive axis O in the first impeller chamber 15. Similarly, the second impeller 7 rotates around the drive axis O in the second impeller chamber 17. The drive axis O is parallel to the front-rear direction of the turbo fluid machine.

[0076] The first to third gaskets 31 to 33 shown in Figs. 1 and 2 are all formed of a metal plate material. Although detailed illustration is omitted, both sides of the first to third gaskets 31 to 33 are provided with a rubber layer. The first gasket 31 is formed in a circular shape along the second front body part 121 of the second front end face 12a, and is disposed on the second front body part 121. That is, the first gasket 31 is disposed on the inner periphery side of the second front outer periphery part 122 on the second front end face 12a. As shown in Fig. 2, the first gasket 31 is formed with a first through portion 31a that penetrates the first gasket 31 in the front-rear direction. Although detailed illustration is omitted, the first through portion 31a is formed in a shape that follows the first impeller chamber 15. The first to third gaskets 31 to 33 may be formed only from a metal plate material.

[0077] As shown in FIG. 3 and FIG. 5, the second gasket 32 ​​is formed in a circular shape along the third front body portion 131 of the third front end surface 13a. The second gasket 32 ​​is formed with the second through-hole 32a, the first engagement hole 32b and the second engagement hole 32c. The second through-hole 32a and the first and second engagement holes 32b, 32c all penetrate the second gasket 32 ​​in the front-rear direction. The second through-hole 32a is formed in a shape along the second impeller chamber 17. The first and second engagement holes 32b, 32c are formed in a circular shape. The second gasket 32 ​​positions the first positioning protrusion 131a in the first engagement hole 32b and positions the second positioning protrusion 131b in the second engagement hole 32c. As a result, the second gasket 32 ​​is positioned on the third front body portion 131 while being positioned on the third front end surface 13a. Thus, the second gasket 32 ​​is disposed on the inner peripheral side of the third front outer circumferential portion 132 on the third front end face 13a.

[0078] Further, the second gasket 32 ​​is formed with a bead 32d that protrudes forward, i.e., toward the second rear body portion 123 of the second rear end face 12b. The bead 32d goes around the periphery of the second through-hole 32a. As a result, the bead 32d surrounds the second impeller chamber 17 from the outer periphery. Although not shown, the first gasket 31 is also positioned on the second front end face 12a like the second gasket 32, and a bead that surrounds the first impeller chamber 15 from the outer periphery is formed.

[0079] As shown in FIG. 4 and FIG. 6, the third gasket 33 is formed in an annular shape along the fourth front body portion 141 of the fourth front end face 14a. The third gasket 33 is formed with a third engagement hole 33a and a fourth engagement hole 33b penetrating the third gasket 33 in the front-rear direction. Like the first and second engagement holes 32b and 32c, the third and fourth engagement holes 33a and 33b are also formed in a circular shape. The third gasket 33 positions the third positioning protrusion 141a in the third engagement hole 33a, and positions the fourth positioning protrusion 141b in the fourth engagement hole 33b. As a result, the third gasket 33 is positioned on the fourth front body portion 141 while being positioned on the fourth front end face 14a. That is, the third gasket 33 is positioned on the outer periphery side of the motor chamber 140.

[0080] In this turbo fluid machine, the first to fourth housings 11 to 14 and the first to third gaskets 31 to 33 are fastened by the first to fourth fastening bolts 19a to 19d as described above, so that the first gasket 31 is disposed in the first divided portion 21 and sandwiched between the first rear body portion 111 and the second front body portion 121, as shown in Fig. 2. The second gasket 32 ​​is disposed in the second divided portion 22 and sandwiched between the second rear body portion 123 and the third front body portion 131. The third gasket 33 is disposed in the third divided portion 23 and sandwiched between the third rear body portion 133 and the fourth front body portion 141.

[0081] Thus, the first gasket 31 seals between the first impeller chamber 15 and the outside of the housing 1. The second gasket 32 ​​seals between the second impeller chamber 17 and the outside of the housing 1. The third gasket 33 seals between the motor chamber 140 and the outside of the housing 1. Here, the motor chamber 140 communicates with the second impeller chamber 17 and the first impeller chamber 15 through the second shaft hole 37 and the first shaft hole 27. Therefore, the third gasket 33 also seals between the first impeller chamber 15 and the second impeller chamber 17 and the outside of the housing 1.

[0082] In addition, in this turbo fluid machine, the first rear outer periphery 112 of the first rear end face 11b and the second front outer periphery 122 of the second front end face 12a abut in the front-rear direction. Also, the second rear outer periphery 124 of the second rear end face 12b and the third front outer periphery 132 of the third front end face 13a abut in the front-rear direction. And the third rear outer periphery 134 of the third rear end face 13b and the fourth front outer periphery 142 of the fourth front end face 14a abut in the front-rear direction.

[0083] Although not shown, gaskets are also provided between the first block 61 and the second block 62, and between the second block 62 and the third block 63 in the fourth housing 14.

[0084] In the turbo fluid machine configured as described above, when electricity is supplied from the power supply device to the electric motor 3 shown in Fig. 1, the electric motor 3 is operated and the drive shaft 9 rotates around the drive shaft center O. As a result, the first impeller 5 rotates around the drive shaft center O in the first impeller chamber 15, and the second impeller 7 rotates around the drive shaft center O in the second impeller chamber 17.

[0085] As a result, the refrigerant gas drawn into the motor chamber 140 through the first suction port 41 flows through the second shaft hole 37 and is drawn into the second impeller chamber 17. The refrigerant gas drawn into the second impeller chamber 17 flows from the inner peripheral side to the outer peripheral side of the second impeller chamber 17 while being compressed by the second impeller 7. In this way, the refrigerant gas compressed by the second impeller 7 is discharged from the first discharge port 29 and flows through the piping 200.

[0086] Then, the refrigerant gas flowing through the piping 200 is sucked into the first impeller chamber 15 through the second suction port 25. As a result, the refrigerant gas flows from the inner peripheral side to the outer peripheral side of the first impeller chamber 15 while being further compressed by the first impeller 5, and is discharged from the second discharge port to the outside of the housing 1. In this manner, in this turbo fluid machine, the refrigerant gas is compressed in two stages by the second impeller 7 and the first impeller 5.

[0087] In this turbo fluid machine, first to third gaskets 31 to 33 are provided in the first to third divided portions 21 to 23, respectively. The first gasket 31 provides a seal between the first impeller chamber 15 and the outside of the housing 1. The second gasket 32 ​​provides a seal between the second impeller chamber 17 and the outside of the housing 1. The third gasket 33 provides a seal between the first and second impeller chambers 15, 17 and the motor chamber 140 and the outside of the housing 1.

[0088] Furthermore, by providing the first to third gaskets 31 to 33 in this manner, it is possible to reduce the radial size of the first to fourth housings 11 to 14, and ultimately the housing 1, of this turbo fluid machine compared to a case in which an O-ring is used to seal between the first and second impeller chambers 15, 17 and the outside of the housing 1, or to seal between the motor chamber 140 and the outside of the housing 1.

[0089] Here, in this turbo fluid machine, the refrigerant gas is compressed to high pressure by the first impeller 5 and the second impeller 7, so that the first impeller chamber 15 and the second impeller chamber 17 are under high pressure. In this regard, in this turbo fluid machine, the first to third gaskets 31 to 33 are made of metal, so that the first to third gaskets 31 to 33 have sufficient rigidity to withstand the pressure of the refrigerant gas in the first and second impeller chambers 15 and 17. Therefore, in this turbo fluid machine, the first to third gaskets 31 to 33 can suitably seal between the first and second impeller chambers 15 and 17 and the motor chamber 140 and the outside of the housing 1.

[0090] In addition, since the first to third gaskets 31-33 are made of metal, in this turbo fluid machine, the first to third gaskets 31-33 are easy to form, and the first to third gaskets 31-33 themselves are inexpensive. Furthermore, in this turbo fluid machine, it is also possible to easily assemble the first to fourth housings 11-14 and the first to third gaskets 31-33.

[0091] In this turbo fluid machine, second front outer periphery 122 of second front end face 12a is located on the outer periphery of first gasket 31 and protrudes forward beyond first gasket 31. Similarly, third front outer periphery 132 of third front end face 13a is located on the outer periphery of second gasket 32 ​​and protrudes forward beyond second gasket 32. Moreover, fourth front outer periphery 142 of fourth front end face 14a is located on the outer periphery of third gasket 33 and protrudes forward beyond third gasket 33.

[0092] Therefore, when the first to fourth housings 11 to 14 are fastened together by the first to fourth fastening bolts 19a to 19d, the second front outer peripheral portion 122 abuts against the first rear outer peripheral portion 112 of the first rear end face 11b on the outer periphery side of the first gasket 31. As shown by the mesh pattern in FIG. 5, the third front outer peripheral portion 132 abuts against the second rear outer peripheral portion 124 of the second rear end face 12b on the outer periphery side of the second gasket 32. At this time, the entire third front outer peripheral portion 132 abuts against the entire second rear outer peripheral portion 124. As shown by the mesh pattern in FIG. 6, the fourth front outer peripheral portion 142 abuts against the third rear outer peripheral portion 134 of the third rear end face 13b on the outer periphery side of the third gasket 33. At this time, the entire fourth front outer peripheral portion 142 also abuts against the entire third rear outer peripheral portion 134. Although not shown in the drawings, the second front outer peripheral portion 122 also comes into contact with the first rear outer peripheral portion 112 in its entirety.

[0093] 2, the second front outer periphery 122 abuts against the first rear outer periphery 112 forward of the first gasket 31. Similarly, the third front outer periphery 132 abuts against the second rear outer periphery 124 forward of the second gasket 32. And the fourth front outer periphery 142 abuts against the third rear outer periphery 134 forward of the third gasket 33.

[0094] In this manner, in this turbo fluid machine, in the first housing 11 and the second housing 12, the first rear end face 11b and the second front end face 12a not only indirectly abut on each other via the first gasket 31, but also directly abut on the outer circumferential side of the first gasket 31. Similarly, in the second housing 12 and the third housing 13, the second rear end face 12b and the third front end face 13a not only indirectly abut on each other via the second gasket 32, but also directly abut on the outer circumferential side of the second gasket 32. And, in the third housing 13 and the fourth housing 14, the third rear end face 13b and the fourth front end face 14a not only indirectly abut on each other via the third gasket 33, but also directly abut on the outer circumferential side of the third gasket 33.

[0095] 2, the second front outer periphery 122 and the first rear outer periphery 112 come into contact with each other, so that in this turbo fluid machine, a clearance for disposing the first gasket 31 can be suitably secured between the first divided portion 21, more specifically, the second front main body portion 121 and the first rear main body portion 111. Similarly, the third front outer periphery 132 and the second rear outer periphery 124 come into contact with each other, so that a clearance for disposing the second gasket 32 ​​can be suitably secured between the third front main body portion 131 and the second rear main body portion 123. Furthermore, the fourth front outer periphery 142 and the third rear outer periphery 134 come into contact with each other, so that a clearance for disposing the third gasket 33 can be suitably secured between the fourth front main body portion 141 and the third rear main body portion 133.

[0096] As a result, in this turbo fluid machine, the first gasket 31 preferably abuts against the second front body portion 121 and the first rear body portion 111. Also, the second gasket 32 ​​preferably abuts against the third front body portion 131 and the second rear body portion 123. Furthermore, the third gasket 33 preferably abuts against the fourth front body portion 141 and the third rear body portion 133.

[0097] Therefore, according to the turbo fluid machine of the first embodiment, leakage of refrigerant gas from the first and second impeller chambers 15, 17 and the motor chamber 140 to the outside of the housing 1 can be suitably prevented, while miniaturization and low manufacturing costs can be achieved.

[0098] In particular, in this turbo fluid machine, the second front outer peripheral portion 122, the third front outer peripheral portion 132, and the fourth front outer peripheral portion 142 are in contact with the first rear outer peripheral portion 112, the second rear outer peripheral portion 124, and the third rear outer peripheral portion 134 on the outer circumferential sides of the first to third gaskets 31 to 33. In this respect, too, in this turbo fluid machine, it is possible to facilitate the assembly of the first to fourth housings 11 to 14 and the first to third gaskets 31 to 33.

[0099] Also, in this turbo fluid machine, the second front outer periphery portion 122, the third front outer periphery portion 132, and the fourth front outer periphery portion 142 are in contact with the first rear outer periphery portion 112, the second rear outer periphery portion 124, and the third rear outer periphery portion 134 at positions shifted forward from the first to third gaskets 31 to 33. Therefore, in this turbo fluid machine, it is easy to bring the second front outer periphery portion 122, the third front outer periphery portion 132, and the fourth front outer periphery portion 142 into contact with the first rear outer periphery portion 112, the second rear outer periphery portion 124, and the third rear outer periphery portion 134, respectively.

[0100] Here, the first rear outer periphery 112 is recessed forward of the first rear main body 111 in correspondence with the second front outer periphery 122. Similarly, the second rear outer periphery 124 is recessed forward of the second rear main body 123 in correspondence with the third front outer periphery 132. Also, the third rear outer periphery 134 is recessed forward of the third rear main body 133 in correspondence with the fourth front outer periphery 142. For these reasons, the first to third divided parts 21 to 23 have a stepped shape in which the outer periphery side is bent forward. As a result, in this turbo fluid machine, it is easy to position the first housing 11 and the second housing 12, the second housing 12 and the third housing 13, and the third housing 13 and the fourth housing 14.

[0101] In addition, since the outer circumferential sides of the first to third divided portions 21 to 23 have a stepped shape that is bent forward, this turbo fluid machine makes it possible to minimize the inevitable leakage of refrigerant gas that occurs in the first to third divided portions 21 to 23.

[0102] Furthermore, in this turbo fluid machine, a bead 32d is formed on the second gasket 32. This makes it possible for the second gasket 32 ​​to be brought into contact with the second rear main body portion 123 with high reliability via the bead 32d. The same applies to the first gasket 31.

[0103] Example 2 7, in the turbo fluid machine of the second embodiment, a first inner abutment portion 125 is formed on the second front body portion 121 of the second front end face 12a. Also, a second inner abutment portion 135 is formed on the third front body portion 131 of the third front end face 13a.

[0104] The first inner abutment portion 125 is disposed on the inner peripheral side of the first penetrating portion 31a, and protrudes forward from the second front main body portion 121. Although detailed illustration is omitted, the first inner abutment portion 125 is formed in a shape that goes around the first impeller chamber 15 along the first impeller chamber 15. As a result, the first inner abutment portion 125 constitutes the inner wall of the first impeller chamber 15.

[0105] 8, the second inner abutment portion 135 is disposed on the inner peripheral side of the second penetrating portion 32a, and protrudes forward from the third front main body portion 131. The second inner abutment portion 135 is formed in a shape that goes around the second impeller chamber 17 along the second impeller chamber 17. As a result, the second inner abutment portion 135 constitutes the inner wall of the second impeller chamber 17. The bead 32d is located outside the second inner abutment portion 135, and surrounds the second inner abutment portion 135.

[0106] 7, in this turbo fluid machine, unlike the turbo fluid machine of the first embodiment, the third rear end face 13b does not have a third rear main body portion 133 and a third rear outer circumferential portion 134. Similarly, the fourth front end face 14a does not have a fourth front main body portion 141 and a fourth front outer circumferential portion 142. In this turbo fluid machine, as shown in FIG. 9, the third gasket 33 is formed with insertion holes 331-334 through which the first to fourth fastening bolts 19a-19d are inserted, respectively.

[0107] Furthermore, in this turbo fluid machine, a third inner abutment portion 143 is formed on the fourth front end face 14a. The third inner abutment portion 143 is disposed on the inner circumferential side of the third gasket 33, and protrudes forward in an annular shape from the fourth front main body portion 141. Other configurations of this turbo fluid machine are similar to those of the turbo fluid machine of the first embodiment, and the same configurations are denoted by the same reference numerals, and detailed description of the configurations will be omitted.

[0108] As in the turbo fluid machine of the first embodiment, in this turbo fluid machine, the first to fourth housings 11 to 14 are fastened by the first to fourth fastening bolts 19a to 19d in a state where the first to third gaskets 31 to 33 are arranged in the first to third divided parts 21 to 23, respectively. At this time, in the third gasket 33, the insertion holes 331 to 334 are aligned with the insertion holes 49a to 49d, respectively. Then, the first to fourth fastening bolts 19a to 19d are inserted into the insertion holes 331 to 334 and the insertion holes 49a to 49d, so that the third gasket 33 is positioned on the fourth front end face 14a. In this state, the third gasket 33 is sandwiched between the third rear end face 13b and the fourth front end face 14a.

[0109] Thus, in this turbo fluid machine as well, similarly to the turbo fluid machine of the first embodiment, the first and second impeller chambers 15, 17 and the motor chamber 140 are sealed from the outside of the housing 1 by the first to third gaskets 31-33.

[0110] As shown in FIG. 7, in this turbo fluid machine, the first to fourth housings 11 to 14 are fastened together by the first to fourth fastening bolts 19a to 19d, so that the first inner abutment portion 125 abuts against the first rear body portion 111 of the first rear end face 11b on the inner periphery of the first gasket 31. As shown by the mesh pattern in FIG. 8, the second inner abutment portion 135 abuts against the second rear body portion 123 of the second rear end face 12b on the inner periphery of the second gasket 32. At this time, the second inner abutment portion 135 abuts against the second rear body portion 123 in its entirety. Then, the second inner abutment portion 135 abuts against the second rear body portion 123 in this way, so that the second impeller chamber 17 is formed between the second housing 12 and the third housing 13. Although detailed illustration is omitted, the same is true for the first inner abutment portion 125.

[0111] 9, the third inner abutment portion 143 abuts against the third rear end face 13b on the inner circumferential side of the third gasket 33. At this time, the third inner abutment portion 143 also abuts against the third rear end face 13b in its entirety.

[0112] In this manner, in this turbo fluid machine, the first housing 11 and the second housing 12 not only indirectly abut on the first gasket 31 at the first rear end face 11b and the second front end face 12a, but also directly abut on the inner circumferential side of the first gasket 31. Similarly, the second housing 12 and the third housing 13 not only indirectly abut on the second rear end face 12b and the third front end face 13a, but also directly abut on the inner circumferential side of the second gasket 32. And the third housing 13 and the fourth housing 14 not only indirectly abut on the third rear end face 13b and the fourth front end face 14a, but also directly abut on the inner circumferential side of the third gasket 33.

[0113] In this manner, by the abutment between the first inner abutment portion 125 and the first rear body portion 111, it is possible to preferably secure a clearance for disposing the first gasket 31 between the second front body portion 121 and the first rear body portion 111 in this turbo fluid machine as well. Similarly, by the abutment between the second inner abutment portion 135 and the second rear body portion 123, it is possible to preferably secure a clearance for disposing the second gasket 32 ​​between the third front body portion 131 and the second rear body portion 123. Furthermore, by the abutment between the third inner abutment portion 143 and the third rear end face 13b, it is possible to preferably secure a clearance for disposing the third gasket 33 between the fourth front end face 14a and the third rear end face 13b.

[0114] Here, in this turbo fluid machine, by abutting the first inner abutment portion 125 with the first rear main body portion 111, it is not necessary to abut the second front outer periphery 122 with the first rear outer periphery 112 in order to ensure a clearance for disposing the first gasket 31. Similarly, in this turbo fluid machine, by abutting the second inner abutment portion 135 with the second rear main body portion 123, it is not necessary to abut the third front outer periphery 132 with the second rear outer periphery 124 in order to ensure a clearance for disposing the second gasket 32.

[0115] Furthermore, in this turbo fluid machine, the first to third inner abutment regions 125, 135, 143 all abut against the first rear main body portion 111, the second rear main body portion 123, and the third rear end face 13b on the inner circumferential sides of the first to third gaskets 31 to 33. This makes it possible to easily assemble the first to fourth housings 11 to 14 and the first to third gaskets 31 to 33 in this turbo fluid machine as well.

[0116] 8, the second inner abutment portion 135 is formed along the shape of the second impeller chamber 17. Therefore, in this turbo fluid machine, the second inner abutment portion 135 can also seal between the second impeller chamber 17 and the outside of the housing 1 at a position closer to the second impeller chamber 17 than the bead 32d of the second gasket 32. Although not shown in detail, the first inner abutment portion 125 can also seal between the first impeller chamber 15 and the outside of the housing 1. Other functions of this turbo fluid machine are similar to those of the turbo fluid machine of the first embodiment.

[0117] (Modification) 10, in the turbo fluid machine of the modified example, the second gasket 32 ​​is formed in a substantially elliptical shape corresponding to the second impeller chamber 17, rather than a circular shape along the third front body portion 131. Other configurations of the turbo fluid machine of the modified example are similar to those of the turbo fluid machine of the second embodiment.

[0118] In this turbo fluid machine, the second gasket 32 ​​can be made smaller than in the turbo fluid machines of Examples 1 and 2. Therefore, this turbo fluid machine can be made more inexpensively. Other functions of this turbo fluid machine are similar to those of the turbo fluid machines of Examples 1 and 2.

[0119] In the above, the present invention has been described in accordance with the first, second and modified examples. However, the present invention is not limited to the above first, second and modified examples, and it goes without saying that the present invention can be applied with appropriate modifications without departing from the spirit of the present invention.

[0120] For example, a turbo fluid machine may be configured by appropriately combining the first and second embodiments and the modified examples. As a result, for example, the first rear end face 11b and the second front end face 12a, and the second rear end face 12b and the third front end face 13a may directly abut on the outer periphery of the first and second gaskets 31 and 32, respectively, and the third rear end face 13b and the fourth front end face 14a may directly abut on the inner periphery of the third gasket 33.

[0122] Furthermore, the second impeller 7 and the second impeller chamber 17 may be omitted to form a turbo fluid machine.

[0123] In the turbo fluid machines of the second embodiment and the modified example, the first inner abutment portion 125 and the first rear main body portion 111 may be in contact with each other, while the second front outer periphery portion 122 and the first rear outer periphery portion 112 may also be in contact with each other. Similarly, the second inner abutment portion 135 and the second rear main body portion 123 may be in contact with each other, while the third front outer periphery portion 132 and the second rear outer periphery portion 124 may also be in contact with each other.

[0124] Furthermore, in the turbo fluid machines of the second embodiment and the modified example, a first inner abutment portion 125 may be formed so as to protrude rearward relative to the first rear body portion 111. Similarly, a second inner abutment portion 135 may be formed so as to protrude rearward relative to the second rear body portion 123, and a third inner abutment portion 143 may be formed so as to protrude rearward relative to the third rear end face 13b.

[0125] Moreover, the configuration of the second gasket 32 ​​in the turbo fluid machine of the modified example may be applied to the first gasket 31.

[0126] Furthermore, in the turbo fluid machines of the first and second embodiments and the modified example, the first and second impellers 5, 7 compress the refrigerant gas as a fluid, but this is not limiting, and the first and second impellers 5, 7 may compress a fluid other than the refrigerant gas. Examples of the fluid other than the refrigerant gas include air and hydrogen to be supplied to a fuel cell. [Industrial Applicability]

[0127] The present invention can be used in vehicle air conditioners and the like. [Explanation of symbols]

[0128] 1. Housing 3. Electric motor 5…First impeller 7…Second impeller 9…Drive shaft 11…1st housing 12…Second housing 13…Third housing 14…4th Housing 15…First impeller chamber 17…Second impeller chamber 31…First gasket 32…Second gasket 33…Third gasket 140…Motor room

Claims

1. a housing in which an impeller chamber and a motor chamber for accommodating an electric motor are formed; an impeller housed in the impeller chamber and compressing a fluid by rotation of the electric motor; a drive shaft accommodated in the housing, extending in an axial direction and connecting the impeller and the electric motor; a gasket formed of a metal plate material for sealing a gap between the impeller chamber and the outside of the housing, The housing includes a first housing and a second housing that defines the impeller chamber together with the first housing. The first housing and the second housing are arranged in the axial direction, The gasket is provided between the first housing and the second housing in the axial direction, the first housing has an end surface facing the second housing in the axial direction, the second housing has an end surface facing an end surface of the first housing in the axial direction, an end surface of the first housing has a first main body portion that abuts against the gasket in the axial direction and a first outer circumferential portion that is located on an outer periphery of the gasket and the first main body portion; an end surface of the second housing includes a second main body portion that abuts against the gasket in the axial direction and sandwiches the gasket between the second main body portion and the second outer circumferential portion located on an outer periphery of the gasket and the second main body portion, The first outer circumferential portion and the second outer circumferential portion directly contact each other in the axial direction at a position on the outer circumferential side of the gasket and spaced apart in the axial direction from the gasket, the first main body portion, and the second main body portion, a boundary portion between an end face of the first housing and an end face of the second housing having a stepped shape that is bent in the axial direction, the boundary portion being formed by the first main body portion, the second main body portion, the first outer circumferential portion, and the second outer circumferential portion.

2. A housing in which an impeller chamber and a motor chamber for accommodating an electric motor are formed, an impeller housed in the impeller chamber and compressing a fluid by rotation of the electric motor; a drive shaft accommodated in the housing, extending in an axial direction and connecting the impeller and the electric motor; a metal gasket for sealing between the impeller chamber and the outside of the housing, The housing includes a first housing and a second housing that defines the impeller chamber together with the first housing. The first housing and the second housing are arranged in the axial direction, The gasket is provided between the first housing and the second housing in the axial direction, The turbo fluid machine, wherein the first housing and the second housing abut in the axial direction only on an inner circumferential side of the gasket.

3. The turbo fluid machine according to claim 2 , wherein the first housing and the second housing are in contact with each other at a position spaced apart in the axial direction from the gasket.

4. the impeller chamber includes a first impeller chamber formed by the first housing and the second housing, and a second impeller chamber located between the first impeller chamber and the motor chamber in the axial direction and communicating with the first impeller chamber, The housing includes a third housing that defines the second impeller chamber together with the second housing, The second housing and the third housing are arranged in the axial direction, the gasket includes a first gasket provided between the first housing and the second housing in the axial direction and configured to seal between the first impeller chamber and an outside of the housing, and a second gasket provided between the second housing and the third housing in the axial direction and configured to seal between the second impeller chamber and the outside of the housing, The turbo fluid machine according to claim 1 , wherein the second housing and the third housing abut in the axial direction on at least one of an outer circumferential side and an inner circumferential side of the second gasket.

5. The turbo-type fluid machine according to claim 4 , wherein the first housing and the second housing, and the second housing and the third housing are in contact only on the outer circumferential side or the inner circumferential side of the first gasket and the second gasket.

6. The housing includes a fourth housing that defines the motor chamber together with the third housing, The third housing and the fourth housing are arranged in the axial direction, the gasket includes a third gasket that is provided between the third housing and the fourth housing in the axial direction and seals between the second impeller chamber and the motor chamber and between the outside of the housing, 6. The turbo fluid machine according to claim 4, wherein the third housing and the fourth housing are in contact with each other in the axial direction at least on one of an outer circumferential side and an inner circumferential side of the third gasket.

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