Rotary machine

Abstract

To provide a rotary machine with a simple structure that can reduce thrust force even when the thrust force is reversed.SOLUTION: A rotary machine comprises: a rotary shaft; a thrust disk part that is provided to the rotary shaft and extends along a radial direction of the rotary shaft; a casing having a one-side flow passage that is formed between the casing and an end face of the thrust disk part on one side in the axial direction, an other-side flow passage that is formed between the casing and an end face of the thrust disk part on the other side in the axial direction, and an outer peripheral-side flow passage that is connected to outer sides of the one-side flow passage and the other-side flow passage in the radial direction; a one-side thrust bearing that is a gas bearing disposed in the one-side flow passage; an other-side thrust bearing that is a gas bearing disposed in the other-side flow passage; and a one-side throat formation part that is provided to the outer peripheral-side flow passage and that forms, between the one-side throat formation part and the outer peripheral surface of the thrust disk part, a throat having a smaller flow passage area than the one-side flow passage, when the thrust disk part is positioned on the one side with respect to an intermediate position in the axial direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to rotary machines. [Background technology]

[0002] BACKGROUND ART Gas bearings are sometimes used as thrust bearings that receive thrust forces from rotary machines such as superchargers (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. WO2022 / 172668 Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, rotary machines such as turbochargers are designed with the assumption that thrust force acts in one axial direction. However, depending on the operating point, the thrust force may act in the other axial direction. In this case, the design that takes into account the thrust force acting in one axial direction may cause the thrust force to increase. Furthermore, while it has been considered to adjust the thrust force by adjusting the pressure on both sides of the thrust disk using a pressure regulator, a rotary machine equipped with a pressure regulator may have a complicated structure. If the axial length of the rotary machine increases due to the complicated structure, there is a risk of increasing the axial vibration of the rotary machine.

[0005] In view of the above circumstances, an object of at least one embodiment of the present disclosure is to provide a rotary machine with a simple structure that is capable of reducing a thrust force even when the thrust force is reversed. [Means for solving the problem]

[0006] A rotary machine according to at least one embodiment of the present disclosure includes: A rotating shaft; a one-side impeller attached to one side of the rotary shaft in the axial direction; a thrust disk portion provided on the rotary shaft and extending along a radial direction of the rotary shaft; a casing configured to rotatably accommodate the rotating shaft and the thrust disk portion, the casing including: a one-side flow passage formed between an end face on one side in the axial direction of the thrust disk portion and the casing; a second-side flow passage formed between an end face on the other side in the axial direction of the thrust disk portion and the casing; and an outer circumferential side flow passage connected to outer sides of the one-side flow passage and the second-side flow passage in the radial direction; a one-side thrust bearing that is a gas bearing disposed in the one-side flow path; a second-side thrust bearing that is a gas bearing disposed in the second-side flow path; a one-side throat forming portion that is provided in the outer peripheral side flow path and that forms a throat with a flow path area smaller than that of the one-side flow path between the outer peripheral surface of the thrust disk portion and the one-side flow path when the thrust disk portion is positioned on the one side of the axial intermediate position. [Effects of the Invention]

[0007] According to at least one embodiment of the present disclosure, a rotary machine is provided that has a simple structure and is capable of reducing a thrust force even when the thrust force is reversed. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic cross-sectional view of a rotary machine taken along an axial direction according to an embodiment of the present disclosure; [Figure 2] 1 is a schematic cross-sectional view taken along the axial direction of a rotary machine near a thrust disk portion according to an embodiment of the present disclosure; [Figure 3] 1 is a schematic view of a thrust disk portion and its vicinity of a rotary machine according to an embodiment of the present disclosure, viewed from the outside in the radial direction; [Figure 4] 2 is a schematic view of the outer periphery-side flow passage and the cooling gas discharge line shown in FIG. 1, viewed from one side in the axial direction. [Figure 5] FIG. 4 is an explanatory diagram for explaining a one-side throat forming portion according to an embodiment of the present disclosure. [Figure 6] FIG. 10 is an explanatory diagram for explaining the other-side throat forming portion in the embodiment of the present disclosure. [Figure 7] 1 is a schematic cross-sectional view taken along the axial direction of a rotary machine near a thrust disk portion according to an embodiment of the present disclosure; [Figure 8] 1 is a schematic cross-sectional view taken along the axial direction of a rotary machine near a thrust disk portion according to an embodiment of the present disclosure; [Figure 9] 1 is a schematic cross-sectional view of a rotary machine taken along an axial direction according to an embodiment of the present disclosure; [Figure 10] 1 is a schematic cross-sectional view taken along the axial direction of a rotary machine near a thrust disk portion according to an embodiment of the present disclosure; [Figure 11] 11 is a schematic view of the outer periphery-side flow passage and the cooling gas discharge line shown in FIG. 10 as viewed from one side in the axial direction. FIG. [Figure 12] 1 is a configuration diagram of a refrigeration system including a rotary machine according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, several embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present disclosure.

[0010] In the following description, when simply referring to the upstream side, it refers to the upstream side along the main flow direction of the fluid in the part or area described in the direction. Similarly, in the following description, when simply referring to the downstream side, it refers to the downstream side along the main flow direction of the fluid in the part or area described in the direction.

[0011] (Rotating Machinery) Fig. 1 is a schematic cross-sectional view along the axial direction of a rotary machine 1 according to an embodiment of the present disclosure. As shown in Fig. 1, the rotary machine 1 according to some embodiments includes at least a rotary shaft 2, a one-side impeller 3, a thrust disk portion 21, a casing 5, a one-side thrust bearing 6, and a other-side thrust bearing 7. In the embodiment shown in Fig. 1, the rotary machine 1 further includes a other-side impeller 4, a cooling gas inlet line 11, and a cooling gas outlet line 12. The one-side impeller 3 is attached to one side of the rotary shaft 2 in the axial direction (upper side in Fig. 1). The other-side impeller 4 is attached to the other side of the rotary shaft 2 in the axial direction (lower side in Fig. 1).

[0012] Hereinafter, the direction in which the central axis CA of the rotating shaft 2 extends (the vertical direction in FIG. 1 ) is defined as the axial direction of the rotating shaft 2, the direction perpendicular to the central axis CA is defined as the radial direction of the rotating shaft 2, and the circumferential direction around the central axis CA is defined as the circumferential direction of the rotating shaft 2. In this disclosure, the axial direction, radial direction, and circumferential direction of the rotating shaft 2 may be simply referred to as the axial direction, radial direction, and circumferential direction, respectively. One side and the other side in the axial direction of the rotating shaft 2 may be simply referred to as the one side and the other side, respectively. Note that in this disclosure, "along a certain direction" includes not only a certain direction but also a direction inclined within a range of ±15° relative to the certain direction.

[0013] (one impeller, other impeller) In the illustrated embodiment, the one-side impeller 3 is a compressor impeller configured to compress gas (e.g., air). The other-side impeller 4 is a turbine rotor configured to be rotated by gas (e.g., air). That is, the rotary machine 1 is a turbocharger. In the illustrated example, the one-side impeller (compressor impeller) 3 is a centrifugal impeller configured to guide gas introduced from the one side along the axial direction to the outside in the radial direction. The other-side impeller (turbine rotor) 4 is a centrifugal turbine configured to guide gas introduced from the outside in the radial direction to the other side along the axial direction.

[0014] Note that some embodiments of the present disclosure are also applicable to cases where the rotary machine 1 is a single-stage centrifugal compressor or a two-stage centrifugal compressor. A single-stage centrifugal compressor is a rotary machine 1 including only one of the first impeller 3 and the second impeller 4. In a two-stage centrifugal compressor, the second impeller 4 is a compressor impeller configured to compress gas (e.g., air). The second impeller (compressor impeller) 4 is, for example, a centrifugal impeller configured to guide gas introduced from the second side along the axial direction to the outside in the radial direction. The two-stage centrifugal compressor is configured to include a gas introduction line for introducing gas compressed by either the first impeller 3 or the second impeller 4 to the other of the first impeller 3 or the second impeller 4. The gas introduced into the first impeller 3 or the second impeller 4, i.e., the gas (refrigerant) circulating in a refrigeration system 300 described later, may be a gas other than air, such as nitrogen gas.

[0015] (Thrust disc part) 1, the thrust disk portion 21 is provided between the one-side impeller 3 and the other-side impeller 4 in the axial direction of the rotating shaft 2, i.e., on the other side of the one-side impeller 3 and on the one side of the other-side impeller 4, and extends along the radial direction of the rotating shaft 2. The thrust disk portion 21 may be formed integrally with the rotating shaft 2, or may be a separate body from the rotating shaft 2 and attached to the rotating shaft 2 by, for example, fitting.

[0016] 2 is a schematic cross-sectional view along the axial direction near the thrust disk portion 21 of the rotary machine 1 according to an embodiment of the present disclosure. As shown in FIG. 2, the thrust disk portion 21 has an outer peripheral surface 22, a one-side end face 23 which is the end face on one side in the axial direction, and a other-side end face 24 which is the end face on the other side in the axial direction.

[0017] (Casing) The casing 5 is configured to rotatably house the rotating shaft 2 and the thrust disk portion 21. In the illustrated embodiment, the casing 5 is also configured to rotatably house the one-side impeller 3 and the other-side impeller 4. The casing 5 is configured to support the one-side thrust bearing 6 and the other-side thrust bearing 7 therein.

[0018] In the illustrated embodiment, the casing 5 rotatably accommodates the rotating shaft 2 and the thrust disk portion 21, and includes a bearing housing 51 that supports the one-side thrust bearing 6 and the other-side thrust bearing 7. The casing 5 may further include a one-side housing 52 that is arranged on the one side of the bearing housing 51, and a other-side housing 53 that is arranged on the other side of the bearing housing 51. The one-side housing 52 is fastened to the bearing housing 51, and rotatably accommodates the one-side impeller 3 between the one-side housing 52 and the bearing housing 51. The other-side housing 53 is fastened to the bearing housing 51, and rotatably accommodates the other-side impeller 4 between the one-side housing 52 and the bearing housing 51.

[0019] 2, the casing 5 has a one-side flow passage 501 formed between one-side end face 23 of the thrust disk portion 21 and one-side wall surface 54 of the casing 5, a other-side flow passage 502 formed between the other-side end face 24 of the thrust disk portion 21 and the other-side wall surface 55 of the casing 5, and an outer-periphery-side flow passage 503 connected to the radially outer sides of the one-side flow passage 501 and the other-side flow passage 502. The one-side flow passage 501 is provided on the one axial side of the thrust disk portion 21. The other-side flow passage 502 is provided on the other axial side of the thrust disk portion 21. In the illustrated embodiment, the one-side flow passage 501, the other-side flow passage 502, and the outer-periphery-side flow passage 503 are each annular flow passages extending in the circumferential direction.

[0020] The one side wall surface 54 faces the one side end surface 23 of the thrust disk portion 21 via an axial gap. The other side wall surface 55 faces the other side end surface 24 of the thrust disk portion 21 via an axial gap. The casing 5 has an outer periphery side wall surface 56 that defines a part of the outer side of the outer periphery side flow passage 503 in the radial direction.

[0021] (One side thrust bearing, other side thrust bearing) The one-side thrust bearing 6 is a gas bearing and is arranged in the one-side flow path 501 described above. The other-side thrust bearing 7 is a gas bearing and is arranged in the other-side flow path 502 described above. The thrust disk portion 21 is configured to be movable in the axial direction relative to the casing 5 between the one-side thrust bearing 6 and the other-side thrust bearing 7. When the thrust disk portion 21 is located at an intermediate position in the axial direction (see FIG. 2), each of the one-side thrust bearing 6 and the other-side thrust bearing 7 faces the thrust disk portion 21 via an axial gap.

[0022] FIG. 3 is a schematic diagram of the vicinity of the thrust disk unit 21 of the rotary machine 1 according to an embodiment of the present disclosure, viewed from the outside in the radial direction. In the embodiment shown in FIG. 3, the one-side thrust bearing 6 includes a top foil 62, which is a thin metal plate having an end surface 61 facing the one-side end surface 23 via an axial gap, and a flexible elastic foil 63, which is disposed on the one side of the top foil 62 and is elastically deformable when the top foil 62 receives a thrust load. The elastic foil 63 may be a bump foil having a corrugated shape (see FIG. 3) or a mesh foil having a mesh shape. In the embodiment shown in FIG. 3, the one-side thrust bearing 6 may further include a flat support plate 64, which is disposed on the one side of the elastic foil 63 and supports the elastic foil 63. The support plate 64 is supported by the one side wall surface 54 of the casing 5.

[0023] In the embodiment shown in FIG. 3 , the other-side thrust bearing 7 includes a top foil 72, which is a thin metal plate having an end surface 71 facing the other-side end surface 24 via an axial gap, and a flexible elastic foil 73, which is disposed on the other side of the top foil 72 and is elastically deformable when the top foil 72 receives a thrust load. The elastic foil 73 may be a bump foil having a corrugated shape (see FIG. 3 ) or a mesh foil having a mesh pattern. In the embodiment shown in FIG. 3 , the other-side thrust bearing 7 may further include a flat support plate 74, which is disposed on the other side of the elastic foil 73 and supports the elastic foil 73. The support plate 74 is supported on the other-side wall surface 55 of the casing 5. Note that the one-side thrust bearing 6 and the other-side thrust bearing 7 are not limited to the embodiment shown in FIG. 3 .

[0024] The cooling gas present in the one-side flow path 501 and the other-side flow path 502 is pushed out from the radially inner side to the radially outer side (pumped up) as the rotating shaft 2 rotates. Pumping up promotes the supply of cooling gas from the cooling gas inlet line 11 to the one-side flow path 501 and the other-side flow path 502 and the radially outward movement of the cooling gas present in the one-side flow path 501 and the other-side flow path 502, so that the one-side thrust bearing 6 or the other-side thrust bearing 7 can be cooled effectively.

[0025] (journal bearing) 1 , the above-described rotary machine 1 includes a one-side journal bearing 101 that rotatably supports the one side of the rotating shaft 2, and an other-side journal bearing 102 that rotatably supports the other side of the rotating shaft 2. Each of the one-side journal bearing 101 and the other-side journal bearing 102 is a gas bearing, and is accommodated in and supported by a bearing housing 51. In the illustrated embodiment, the one-side journal bearing 101 is arranged on the other side of the thrust disk portion 21. The other-side journal bearing 102 is arranged on the other side of the one-side journal bearing 101.

[0026] (Electric motor) As shown in Fig. 1, a rotary machine 1 according to some embodiments may include a rotor 201 of an electric motor 20 and a stator 202 of the electric motor 20. The rotor 201 includes a permanent magnet 203. In the embodiment shown in Fig. 1, the rotor 201 is attached to the other side of the thrust disk portion 21 of the rotating shaft 2. The stator 202 includes a stationary coil portion 205 and is disposed on the outer circumferential side of the rotor 201, facing the rotor 201 with a radial gap therebetween. An electric motor accommodating space 58 that accommodates the rotor 201 and stator 202 of the electric motor 20 is formed inside the bearing housing 51.

[0027] The rotor 201 further includes a permanent magnet support portion 204 that supports the permanent magnets 203. The permanent magnet support portion 204 is attached to the rotating shaft 2. The stator 202 further includes a stationary coil portion support portion 206 that supports the stationary coil portion 205. The stationary coil portion support portion 206 is supported by the bearing housing 51.

[0028] 1, the rotary machine 1 is an electric supercharger configured such that electric power is supplied to an electric motor 20 from a power source (not shown), thereby driving the electric motor 20 and rotating the rotary shaft 2. Note that some embodiments of the present disclosure are also applicable to a rotary machine 1 that does not include an electric motor 20.

[0029] (Cooling gas introduction line) The cooling gas introduction line 11 is configured to introduce cooling gas from the radially inner side into at least one of the one-side flow path 501 or the other-side flow path 502. In the illustrated embodiment, the cooling gas introduction line 11 includes a one-side cooling gas introduction line 13 configured to introduce cooling gas from the radially inner side into the one-side flow path 501, and a other-side cooling gas introduction line 14 configured to introduce cooling gas from the radially inner side into the other-side flow path 502. The "cooling gas" may be any gas that can flow through the one-side flow path 501 or the other-side flow path 502 to cool the one-side thrust bearing 6 or the other-side thrust bearing 7, and may be, for example, a gas at room temperature (0°C or higher and 40°C or lower) or a gas at a temperature lower than room temperature. The cooling gas is introduced from the radially inner side into at least one of the one-side flow path 501 or the other-side flow path 502 through the cooling gas introduction line 11.

[0030] In the illustrated embodiment, the one-side cooling gas introduction line 13 includes an inner annular passage 15 extending in the circumferential direction and a cooling gas introduction passage 17 for introducing cooling gas into the inner annular passage 15. The inner annular passage 15 is formed inside the bearing housing 51 (casing 5) and connected to the radially inner side of the one-side passage 501. In the embodiment shown in FIG. 1 , the cooling gas introduction passage 17 is connected to a space formed between the back surface of the one-side impeller (compressor impeller) 3 and the end face of the bearing housing 51, and gas compressed by the one-side impeller 3 is introduced therein. Note that in some other embodiments, the cooling gas introduction passage 17 may be configured to introduce cooling gas from outside the bearing housing 51 (casing 5). For example, the cooling gas introduction passage 17 may have an introduction-side outer opening formed on the outer surface 57 of the bearing housing 51 (casing 5). The one-side cooling gas introduction line 13 may be connected to a blower (pressure booster) 103 for pressurizing the cooling gas.

[0031] In the illustrated embodiment, the other-side cooling gas introduction line 14 includes an inner annular passage 16 that is annular and extends along the circumferential direction, and a cooling gas introduction passage 18 that introduces cooling gas into the inner annular passage 16. The inner annular passage 16 is formed inside the bearing housing 51 (casing 5) and is connected to the radially inner side of the other-side passage 502. In the embodiment shown in FIG. 1 , the cooling gas introduction passage 18 has an introduction-side outer opening 181 formed in the outer surface 57 of the bearing housing 51 (casing 5). The introduction-side outer opening 181 is formed on the other side of the other-side journal bearing 102. The one-side journal bearing 101 and the other-side journal bearing 102 are each disposed in the cooling gas introduction passage 18. The motor accommodating space 58 constitutes a part of the cooling gas introduction passage 18. A blower 103 for pressurizing the cooling gas may be connected to the other-side cooling gas introduction line 14.

[0032] (Cooling gas exhaust line) FIG. 4 is a schematic diagram of the outer periphery-side flow passage 503 and the cooling gas discharge line 12 (12A) shown in FIG. 1 as viewed from one side in the axial direction. In the embodiment shown in FIGS. 1 and 4, the cooling gas discharge line 12 (12A) has a cooling gas discharge passage 121 for guiding the cooling gas from the outer periphery-side flow passage 503 to the outside of the bearing housing 51 (casing 5), a discharge-side inlet opening 122 formed in the outer periphery-side flow passage 503, and a discharge-side outlet opening 123 formed on the outer surface 57 of the bearing housing 51 (casing 5). The cooling gas flows from each of the one-side flow passage 501 and the other-side flow passage 502, through the outer periphery-side flow passage 503 and the cooling gas discharge passage 121 in this order, and is then discharged to the outside of the bearing housing 51. In the embodiment shown in FIGS. 1 and 4, the cooling gas discharge passage 121 extends radially outward from the discharge-side inlet opening 122 along the radial direction.

[0033] (One side throat forming part, other side throat forming part) 5 is an explanatory diagram illustrating one-side throat forming portion 8 according to one embodiment of the present disclosure. As shown in FIG. 5, one-side throat forming portion 8 is provided in outer periphery-side flow passage 503, and when thrust disk portion 21 receives thrust force and is positioned on the one side of the axially intermediate position, forms throat TH1, which has a smaller flow passage area than one-side flow passage 501, between one-side throat forming portion 8 and outer periphery 22 of thrust disk portion 21. Throat TH1 formed by one-side throat forming portion 8 has a smaller flow passage area than other-side flow passage 502.

[0034] As shown in FIG. 5 , when the thrust disk portion 21 receives a thrust force and is positioned to the one side of the axial intermediate position, the one-side end face 23 of the thrust disk portion 21 abuts against the end face 61. The elastic foil 63 is configured to contract in the axial direction before the one-side end face 23 abuts against the end face 61 due to an air film formed between the one-side end face 23 and the end face 61. After the one-side end face 23 abuts against the end face 61, the end face 61 is urged toward the one side in the axial direction by the one-side end face 23, causing the elastic foil 63 to contract in the axial direction. Note that the gas flowing through the one-side flow path 501 continues to flow inside the one-side thrust bearing 6, i.e., through the gap between the top foil 62 and the elastic foil 63 and the gap between the elastic foil 63 and the support plate 64, even after the one-side end face 23 abuts against the end face 61.

[0035] When the thrust disk portion 21 receives a thrust force toward the one side in the axial direction (the right side in FIG. 5) and is positioned further to the one side than the axial intermediate position, the one-side throat forming portion 8 forms the throat TH1, thereby making it possible to increase the static pressure in the one-side flow path 501 to be higher than the static pressure in the other-side flow path 502, and the pressure difference between the one-side flow path 501 and the other-side flow path 502 causes a force to act on the thrust disk portion 21 in the axial direction opposite to the thrust force (the left side in FIG. 5). The rotary machine 1 is only required to be provided with the one-side throat forming portion 8, which has a simple structure, and therefore is capable of reducing the thrust force even when the thrust force is reversed, with a simple structure.

[0036] 6, the other-side throat forming portion 9 is provided in the outer periphery-side flow passage 503, and when the thrust disk portion 21 receives a thrust force and is positioned on the other side of the axial intermediate position, forms a throat TH2 between itself and the outer periphery 22 of the thrust disk portion 21, the throat TH2 having a smaller flow passage area than the other-side flow passage 502. The throat TH2 formed by the other-side throat forming portion 9 has a smaller flow passage area than the one-side flow passage 501.

[0037] As shown in FIG. 6 , when the thrust disk portion 21 receives a thrust force and is positioned further to the other side than the axially intermediate position, the other-side end face 24 of the thrust disk portion 21 abuts against the end face 71. The elastic foil 73 is configured to contract in the axial direction before the other-side end face 24 abuts against the end face 71 due to an air film formed between the other-side end face 24 and the end face 71. After the other-side end face 24 abuts against the end face 71, the end face 71 is urged toward the other side in the axial direction by the other-side end face 24, causing the elastic foil 73 to contract in the axial direction. Note that the gas flowing through the other-side flow path 502 continues to flow through the interior of the other-side thrust bearing 7, i.e., the gap between the top foil 72 and the elastic foil 73 and the gap between the elastic foil 73 and the support plate 74, even after the other-side end face 24 abuts against the end face 71.

[0038] When the thrust disk portion 21 receives a thrust force toward the other side in the axial direction (left side in FIG. 6 ) and is positioned further to the other side than the axial intermediate position, the other-side throat forming portion 9 forms a throat TH2, thereby making it possible to increase the static pressure in the other-side flow path 502 to be higher than the static pressure in the one-side flow path 501. Due to the pressure difference between the one-side flow path 501 and the other-side flow path 502, a force can be applied to the thrust disk portion 21 in the axial direction opposite to the thrust force (right side in FIG. 6 ). Since the rotary machine 1 only needs to be provided with the other-side throat forming portion 9, which has a simple structure, it is possible to reduce the thrust force even when the thrust force is reversed, even with a simple structure. In some other embodiments, the rotary machine 1 may be provided with only one of the one-side throat forming portion 8 or the other-side throat forming portion 9.

[0039] (One side fin) 7 and 8 are schematic cross-sectional views along the axial direction near the thrust disk portion 21 of the rotary machine 1 according to an embodiment of the present disclosure. In the rotary machine 1 according to some embodiments, as shown in FIGS. 2 and 7, the casing 5 has a first-side opposing surface (opposing surface) 56A that faces the first-side thrust bearing 6 across the outer periphery-side flow passage 503, and a second-side opposing surface (opposing surface) 56B that faces the second-side thrust bearing 7 across the outer periphery-side flow passage 503. The first-side opposing surface 56A and the second-side opposing surface 56B are part of the outer periphery-side wall surface 56. The first-side throat forming portion 8 includes at least one first-side fin 81 provided in a portion including the throat forming position. The first-side fin 81 protrudes radially inward beyond the first-side opposing surface 56A and the second-side opposing surface 56B, and its inner peripheral end is at the throat forming position. The first-side fin 81 is preferably thin (thickness: less than 3 mm).

[0040] In this case, when thrust disk portion 21 receives a thrust force and is positioned on the one side of the axial intermediate position, throat TH1 can be formed by one-side fin 81 provided in the portion including the throat formation position. By using one-side fin 81 in the portion including the throat formation position, damage to thrust disk portion 21 and one-side fin 81 can be reduced even if thrust disk portion 21 comes into contact with one-side fin 81.

[0041] 2 and 5 , in the rotary machine 1 according to some embodiments, at least one one-side fin 81 is provided at a position that overlaps with the outer peripheral surface 22 of the thrust disk portion 21 in the axial direction when the thrust disk portion 21 is located on the one side of the axial intermediate position. At least one one-side fin 81 is provided at a position that does not overlap with the outer peripheral surface of the thrust disk portion 21 in the axial direction when the thrust disk portion 21 is located at the axial intermediate position. In other words, the at least one one-side fin 81 is located on the one axial side of the one-side end face 23 when the thrust disk portion 21 is located at the axial intermediate position.

[0042] In this case, it is possible to prevent the flow path area formed between the one-side fins 81 and the outer peripheral surface 22 of the thrust disk portion 21 from becoming smaller when the thrust disk portion 21 is positioned at the intermediate position in the axial direction or on the other side of the intermediate position, and therefore it is possible to prevent the one-side fins 81 from obstructing the flow of cooling gas. Note that at least one one-side fin 81 may be provided at a position that does not overlap with the outer peripheral surface 22 of the thrust disk portion 21 in the axial direction when the thrust disk portion 21 is positioned at a contact position where it is in contact with the one-side thrust bearing 6, that is, an axial position where the thrust disk portion 21 changes from a non-contact state to a contact state with the one-side thrust bearing 6. The at least one one-side fin 81 is provided at a position that overlaps with the outer peripheral surface 22 of the thrust disk portion 21 in the axial direction when the one-side thrust bearing 6 is biased by the thrust disk portion 21 to the one side in the axial direction and the thrust disk portion 21 is positioned on the one side in the axial direction of the contact position.

[0043] 7, in the rotary machine 1 according to some embodiments, the at least one one-side fin 81 includes a first one-side fin 81A and a second one-side fin 81B provided at a position offset in the axial direction from the first one-side fin 81A. In the illustrated embodiment, the second one-side fin 81B is provided on the other side in the axial direction relative to the first one-side fin 81A.

[0044] In this case, by providing the two one-side fins 81A, 81B at positions offset in the axial direction, the throat TH1 can be formed in the one-side fin 81A, 81B appropriate for the axial position of the thrust disk portion 21.

[0045] (other side fin) 2 and 7, in the rotary machine 1 according to some embodiments, the other-side throat forming portion 9 includes at least one other-side fin 91 provided in a portion including the throat forming position. The other-side fin 91 protrudes radially inward beyond the one-side opposing surface 56A and the other-side opposing surface 56B, and its inner peripheral end is at the throat forming position. The other-side fin 91 is preferably thin plate-shaped (thickness less than 3 mm).

[0046] In this case, when thrust disk portion 21 receives a thrust force and is positioned on the other side of the axial intermediate position, throat TH2 can be formed by other-side fin 91 provided in the portion including the throat formation position. By using the other-side fin 91 in the portion including the throat formation position, damage to thrust disk portion 21 and other-side fin 91 can be reduced even if thrust disk portion 21 comes into contact with other-side fin 91.

[0047] 2 and 5 , in the rotary machine 1 according to some embodiments, at least one other-side fin 91 is provided at a position where it overlaps with the outer peripheral surface 22 of the thrust disk portion 21 in the axial direction when the thrust disk portion 21 is located on the other side of the axial intermediate position. At least one other-side fin 91 is provided at a position where it does not overlap with the outer peripheral surface of the thrust disk portion 21 in the axial direction when the thrust disk portion 21 is located at the axial intermediate position. In other words, the at least one other-side fin 91 is located on the other axial side of the other-side end face 24 when the thrust disk portion 21 is located at the axial intermediate position.

[0048] In this case, it is possible to prevent the flow path area formed between the other-side fins 91 and the outer peripheral surface 22 of the thrust disk portion 21 from becoming smaller when the thrust disk portion 21 is positioned at the intermediate position in the axial direction or on the one side of the intermediate position, and therefore it is possible to prevent the other-side fins 91 from obstructing the flow of cooling gas. Note that at least one other-side fin 91 may be provided at a position that does not overlap with the outer peripheral surface 22 of the thrust disk portion 21 in the axial direction when the thrust disk portion 21 is positioned at a contact position where it is in contact with the other-side thrust bearing 7, that is, an axial position where the thrust disk portion 21 changes from a non-contact state to a contact state with the other-side thrust bearing 7. The at least one other-side fin 91 is provided at a position that overlaps with the outer peripheral surface 22 of the thrust disk portion 21 in the axial direction when the other-side thrust bearing 7 is biased by the thrust disk portion 21 toward the other side in the axial direction and the thrust disk portion 21 is positioned on the other side in the axial direction of the contact position.

[0049] 7, in the rotary machine 1 according to some embodiments, the at least one other-side fin 91 includes a first other-side fin 91A and a second other-side fin 91B provided at a position shifted in the axial direction from the first other-side fin 91A. In the illustrated embodiment, the second other-side fin 91B is provided on the one side in the axial direction with respect to the first other-side fin 91A.

[0050] In this case, by providing the two other-side fins 91A, 91B at positions offset in the axial direction, it is possible to form a throat in the appropriate other-side fin 91A, 91B depending on the axial position of the thrust disk portion 21.

[0051] In the rotary machine 1 according to some embodiments, as shown in Fig. 8, the one-side throat forming portion 8 includes a one-side opposing surface (opposing surface) 56A provided in a portion including the throat forming position. When the thrust disk portion 21 receives a thrust force and is positioned on the one side of the axially intermediate position, the opposing surface 56A provided in the portion including the throat forming position can form the throat. In this case, the structure can be simplified compared to when the one-side throat forming portion 8 includes a one-side fin 81.

[0052] In the rotary machine 1 according to some embodiments, as shown in Fig. 8, the other-side throat forming portion 9 includes a second-side opposing surface (opposing surface) 56B provided in a portion including the throat forming position. When the thrust disk portion 21 receives a thrust force and is positioned on the other side of the axially intermediate position, the opposing surface 56B provided in the portion including the throat forming position can form the throat. In this case, the structure can be simplified compared to when the other-side throat forming portion 9 includes the second-side fin 91.

[0053] In the rotary machine 1 according to some embodiments, as shown in FIG. 4 , a portion of the one-side throat forming portion 8 including the throat forming position (the one-side fin 81 in the illustrated example) is formed over a circumferential range of at least one-quarter of the circumference of the rotating shaft 2. The portion of the one-side throat forming portion 8 including the throat forming position is preferably formed over a circumferential range of at least one-third of the circumference of the rotating shaft 2, and more preferably over a circumferential range of at least one-half of the circumference of the rotating shaft 2. As shown in FIG. 4 , a plurality of one-side throat forming portions 8 may be arranged side by side in the circumferential direction. In this case, the circumferential range is the sum of the circumferential ranges of the one-side throat forming portions 8. By providing the one-side throat forming portion 8 over a relatively wide circumferential range, the static pressure of the one-side flow passage 501 can be effectively increased.

[0054] In the rotary machine 1 according to some embodiments, the portion of the other-side throat forming portion 9 including the throat forming position (the other-side fin 91 in the illustrated example) is formed over a circumferential range of at least one-quarter of the circumference of the rotating shaft 2. The portion of the other-side throat forming portion 9 including the throat forming position is preferably formed over a circumferential range of at least one-third of the circumference of the rotating shaft 2, and more preferably over a circumferential range of at least one-half of the circumference of the rotating shaft 2. A plurality of other-side throat forming portions 9 may be arranged side by side in the circumferential direction. In this case, the circumferential range is the sum of the circumferential ranges of the other-side throat forming portions 9. By providing the other-side throat forming portion 9 over a relatively wide circumferential range, the static pressure of the other-side flow passage 502 can be effectively increased.

[0055] 1 and 2 , in the rotary machine 1 according to some embodiments, the cooling gas discharge line 12 (12A) includes a discharge-side inlet opening 122 formed in the outer peripheral wall surface 56. In this case, the cooling gas can be guided to the cooling gas discharge line 12 via the discharge-side inlet opening 122 formed in the outer peripheral wall surface 56.

[0056] In the following embodiments, the same components as those in the above-described embodiments are denoted by the same reference numerals, and description thereof will be omitted. Fig. 9 is a schematic cross-sectional view along the axial direction of a rotary machine 1 according to an embodiment of the present disclosure. Fig. 10 is a schematic cross-sectional view along the axial direction of a rotary machine 1 near a thrust disk portion 21 according to an embodiment of the present disclosure. Fig. 11 is a schematic view of an outer periphery-side flow passage 503 and a cooling gas discharge line 12 shown in Fig. 10 as viewed from one side in the axial direction.

[0057] In a rotary machine 1 according to some embodiments, as shown in FIG. 9 , the above-described thrust disk portion 21 is disposed on the other side of the other-side journal bearing 102. In the embodiment shown in FIG. 9 , the above-described cooling gas introduction passage 17 has an introduction-side outer opening 171 formed in an outer surface 57 of the bearing housing 51 (casing 5). The introduction-side outer opening 171 is formed on the one side of the one-side journal bearing 101. The one-side journal bearing 101 and the other-side journal bearing 102 are each disposed in the cooling gas introduction passage 17. The motor accommodating space 58 constitutes a part of the cooling gas introduction passage 17.

[0058] (Cooling gas exhaust line) 9 to 11, the cooling gas discharge line 12 (12B) has a cooling gas discharge passage 124 for guiding the cooling gas from the outer periphery-side passage 503 to the outside of the bearing housing 51 (casing 5), a discharge-side inlet opening 125 formed in the outer periphery-side passage 503, and a discharge-side outlet opening 126 formed in an end face (illustrated example) on the one or the other axial side of the rotating shaft 2. In the embodiment shown in FIG. 9, the discharge-side outlet opening 126 is formed in the end face on the other axial side of the rotating shaft 2, but it may also be formed in the end face on the one axial side of the rotating shaft 2.

[0059] The discharge-side inlet opening 125 is formed in the outer peripheral surface 22 of the thrust disk portion 21. The cooling gas discharge passage 124 is formed inside the thrust disk portion 21 and the rotating shaft 2. The cooling gas discharge passage 124 includes a first cooling gas discharge passage 124A that extends radially inward from the discharge-side inlet opening 125, and a second cooling gas discharge passage 124B that is connected to the first cooling gas discharge passage 124A and extends along the axial direction. The cooling gas flows from each of the one-side passage 501 and the other-side passage 502, through the outer peripheral-side passage 503, and then through the cooling gas discharge passage 124, and is then discharged to the outside of the bearing housing 51.

[0060] Cooling gas can be introduced into the inside of the thrust disk portion 21 through the discharge side inlet opening 125. By circulating the cooling gas inside the thrust disk portion 21, it is possible to effectively cool the thrust disk portion 21, the one-side thrust bearing 6, and the other-side thrust bearing 7. The cooling gas can be discharged into the gas flow path through the discharge side outlet opening 126.

[0061] 9, the other-side impeller 4 is fixed integrally to the rotating shaft 2 by welding or brazing. In this case, a nut is inserted through a through-hole of the other-side impeller 4 of the rotating shaft 2 and screwed onto the protrusion protruding on the other side, and the other-side impeller 4 is sandwiched between the nut and either another member such as a thrust collar or a stepped surface of the rotating shaft 2, thereby making it easier to form the cooling gas discharge line 12B (particularly the discharge-side outlet opening 126) compared to a nut-type fixing structure in which the other-side impeller 4 is fixed by clamping the other-side impeller 4 between the nut and either another member such as a thrust collar or a stepped surface of the rotating shaft 2.

[0062] In the embodiment shown in FIG. 9 , the other-side impeller 4 has a cylindrical protruding portion 42 that protrudes further toward the one axial direction than the back surface 41 of the other-side impeller 4. The protruding portion 42 extends an inner circumferential surface 43, which defines a through hole that penetrates the other-side impeller 4 along the axial direction, toward the one axial direction. The other-side impeller 4 is integrally fixed to the rotating shaft 2 by inserting the protruding portion 42 into the inner circumferential surface 25 that forms the hollow portion of the rotating shaft 2 and fixing the protruding portion 42 and the inner circumferential surface 25 by welding or brazing. The symbol W shown in FIG. 9 indicates a welded portion between the protruding portion 42 and the inner circumferential surface 25. In this case, a portion of the cooling gas discharge line 12B is formed inside the other-side impeller 4. The discharge-side outlet opening 126 is formed in the end face of the other axial side of the other-side impeller 4. The second cooling gas discharge passage 124B is formed by the inner circumferential surface 25 of the rotary shaft 2 and an inner circumferential surface 43 that communicates with the inner circumferential surface 25 of the impeller 4 on the other side.

[0063] In some other embodiments, the one-side impeller 3 may be integrally fixed to the rotating shaft 2 by welding or brazing. The discharge-side outlet opening 126 may be formed in the end face on one side in the axial direction of the one-side impeller 3. The second cooling gas discharge passage 124B may be formed by an inner circumferential surface that communicates with the inner circumferential surface 25 of the rotating shaft 2 and the inner circumferential surface 25 of the one-side impeller 3. By forming the second cooling gas discharge passage 124B inside either the one-side impeller 3 or the other-side impeller 4 and the rotating shaft 2, the weight of the rotating shaft system of the rotary machine 1 can be reduced. Furthermore, by integrally fixing either the one-side impeller 3 or the other-side impeller 4 to the rotating shaft 2 by welding or brazing, the weight of the nut can be reduced, and the weight of the rotating shaft system of the rotary machine 1 can be reduced. This improves the shaft rigidity of the rotary machine 1.

[0064] 9, when the maximum outer diameter of the rotating shaft 2 including the rotor 201 is defined as D1, the inner diameter of the one-side journal bearing 101 is defined as D2, and the inner diameter of the other-side journal bearing 102 is defined as D3, the conditions D1≦D2 and D1≦D3 are satisfied. In this case, even if either the one-side impeller 3 or the other-side impeller 4 is fixed to the rotating shaft 2 by welding or brazing, the one-side journal bearing 101 and the other-side journal bearing 102 can be easily attached to the rotating shaft 2 including the rotor 201.

[0065] (Turbocharger for refrigeration systems) Fig. 12 is a configuration diagram of a refrigeration system 300 including a rotary machine 1 according to an embodiment of the present disclosure. In the embodiment shown in Fig. 12, the rotary machine 1 is an electric supercharger including a compressor impeller (one-side impeller 3), a turbine rotor (the other-side impeller 4), and an electric motor 20 (a rotor 201 and a stator 202). The refrigeration system 300 includes a gas circulation line 301 for circulating gas. The compressor impeller 3 and the turbine rotor 4 are provided in the gas circulation line 301. The compressor impeller 3 functions as a compressor in the refrigeration system 300, and the turbine rotor 4 functions as an expander in the refrigeration system 300.

[0066] The gas circulation line 301 includes a gas supply line 301A for guiding the gas compressed by the compressor impeller 3 to the turbine rotor 4, and a gas introduction line 301B for guiding the gas expanded by the turbine rotor 4 to the compressor impeller 3.

[0067] 12, the rotary machine 1 includes a cooler 302 for cooling the gas compressed by the compressor impeller 3. In the illustrated embodiment, the cooler 302 is a water-cooled heat exchanger configured to perform heat exchange between cooling water and the gas to cool the gas.

[0068] In the illustrated embodiment, the gas inlet line 301B is provided with a structure (in the illustrated example, a refrigerated container) 303 for accommodating an object to be cooled. The gas inlet line 301B is also provided with a heat exchanger 304 configured to exchange heat between gas flowing downstream of the structure 303 in the gas inlet line 301B and gas flowing downstream of the cooler 302 in the gas supply line 301A. In the refrigeration system 300, the gas introduced into the turbine rotor 4 has a lower temperature than the gas introduced into the compressor impeller 3. Note that, instead of the structure 303, a heat exchanger configured to exchange heat between a refrigerant for cooling the object to be cooled and the gas flowing through the gas inlet line 301B may be provided at the installation position of the structure 303 in the gas inlet line 301B.

[0069] In some embodiments of the rotary machine 1, as shown in FIG. 12, the at least one cooling gas introduction line 11 described above is configured to introduce gas cooled by the cooler 302 into at least one of the one-side flow path 501 or the other-side flow path 502 from the radially inner side.

[0070] In this case, the gas flowing through the cooling gas introduction line 11 can be pressurized by the compressor impeller 3, which can be used in place of the blower 103. In addition, the gas flowing through the cooling gas introduction line 11 is cooled by the cooler 302, so that the one-side thrust bearing 6 and the other-side thrust bearing 7 can be effectively cooled.

[0071] 12, the one-side cooling gas introduction line 13 is connected to the gas supply line 301A downstream of the cooler 302 and upstream of the heat exchanger 304, and the other-side cooling gas introduction line 14 is connected to the one-side cooling gas introduction line 13. In some other embodiments, the one-side cooling gas introduction line 13 and the other-side cooling gas introduction line 14 may be connected to the gas supply line 301A without sharing a common line. In the embodiment shown in FIG. 12, the cooling gas discharge line 12 is connected to the gas introduction line 301B downstream of the structure 303 and the heat exchanger 304. A portion of the gas flowing through the gas circulation line 301 (301A) is guided to the one-side flow path 501 or the other-side flow path 502 via the one-side cooling gas introduction line 13 or the other-side cooling gas introduction line 14. The gas introduced into either one side flow path 501 or the other side flow path 502 flows from either one side flow path 501 or the other side flow path 502, through the outer periphery side flow path 503 and the cooling gas discharge line 12 in that order, and then is returned to the gas circulation line 301 (301B).

[0072] Increasing the pressure rise caused by the compressor impeller 3 in the refrigeration system 300 increases the refrigeration capacity of the refrigeration system 300, but the thrust force acting on the rotary machine 1 increases accordingly, which may result in a decrease in the axial reliability of the rotary machine 1. In the rotary machine 1 according to the embodiment shown in Fig. 12, increasing the pressure rise caused by the compressor impeller 3 increases the pressure of the gas flowing through the one-side cooling gas introduction line 13 and the other-side cooling gas introduction line 14 accordingly, and the static pressure of the one-side flow path 501 and the other-side flow path 502 can also be increased. This ensures the axial reliability of the rotary machine 1.

[0073] In this specification, expressions expressing relative or absolute arrangement such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial" not only express such an arrangement strictly, but also express a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained. For example, expressions such as "identical," "equal," and "homogeneous" that indicate that something is in an equal state not only indicate a state of strict equality, but also indicate a state in which there is a tolerance or a difference to the extent that the same function is obtained. Furthermore, in this specification, expressions representing shapes such as a rectangular shape or a cylindrical shape not only represent rectangular shapes or cylindrical shapes in the strict geometric sense, but also represent shapes including uneven portions, chamfered portions, etc., to the extent that the same effect can be obtained. Furthermore, in this specification, the expressions "comprise," "include," or "have" a component are not exclusive expressions that exclude the presence of other components.

[0074] The present disclosure is not limited to the above-described embodiments, but also includes modifications to the above-described embodiments and appropriate combinations of these modifications.

[0075] The contents of the above-described embodiments can be understood, for example, as follows.

[0076] 1) A rotary machine (1) according to at least one embodiment of the present disclosure includes: a rotating shaft (2); a one-side impeller (3) attached to one side in the axial direction of the rotary shaft (2); a thrust disk portion (21) provided on the rotary shaft (2) and extending along the radial direction of the rotary shaft (2); a casing (5) configured to rotatably accommodate the rotating shaft (2) and the thrust disk portion (21), the casing having: a one-side flow passage (501) formed between the casing and an end face on one side in the axial direction of the thrust disk portion (21); a other-side flow passage (502) formed between the casing and an end face on the other side in the axial direction of the thrust disk portion (21); and an outer circumferential side flow passage (503) connected to the outside of the one-side flow passage (501) and the other-side flow passage (502) in the radial direction; a one-side thrust bearing (6) which is a gas bearing arranged in the one-side flow path (501); a second-side thrust bearing (7) which is a gas bearing arranged in the second-side flow path (502); and a one-side throat forming portion (8) that is provided in the outer circumferential flow path (503) and forms a throat having a flow path area smaller than that of the one-side flow path (501) between the outer circumferential surface of the thrust disk portion (21) and the one-side throat forming portion (8) when the thrust disk portion (21) is positioned on the one side of the axial intermediate position.

[0077] According to the configuration 1), when the thrust disk portion (21) receives a thrust force and is positioned on the one side of the axial intermediate position, the one-side throat forming portion (8) forms a throat, thereby making it possible to increase the static pressure in the one-side flow path (501) to be higher than the static pressure in the other-side flow path (502), and a force acting in the axially opposite direction to the thrust force can be applied to the thrust disk portion (21) due to the pressure difference between the one-side flow path (501) and the other-side flow path (502). The rotary machine (1) is only required to be provided with the one-side throat forming portion (8) having a simple structure, and therefore, with a simple structure, it is possible to reduce the thrust force even when the thrust force is reversed.

[0078] 2) In some embodiments, the rotary machine (1) described in 1) above, The other-side throat forming portion (9) is provided in the outer circumferential flow path (503) and forms a throat having a flow path area smaller than that of the other-side flow path (502) between the outer circumferential surface of the thrust disk portion (21) and the other-side throat forming portion (9) when the thrust disk portion (21) is positioned on the other side of the axial intermediate position.

[0079] According to the configuration 2), when the thrust disk portion (21) receives a thrust force and is positioned on the other side of the axial intermediate position, the other-side throat forming portion (9) forms a throat, thereby making it possible to increase the static pressure in the other-side flow path (502) to be higher than the static pressure in the one-side flow path (501). As a result, a force in the axially opposite direction to the thrust force can be applied to the thrust disk portion (21) due to the pressure difference between the one-side flow path (501) and the other-side flow path (502). The rotary machine (1) only needs to be provided with the other-side throat forming portion (9) having a simple structure, and therefore can reduce the thrust force with a simple structure even when the thrust force is reversed.

[0080] 3) In some embodiments, the rotary machine (1) according to 1) or 2) above, the casing (5) has opposing surfaces (56A, 56B) that face each other across the outer periphery-side flow path (503) between the one-side thrust bearing (6) and the other-side thrust bearing (7), The one-side throat forming portion (8) is provided in a portion including a throat forming position and includes at least one one-side fin (81) that protrudes radially inward beyond the opposing surfaces (56A, 56B).

[0081] According to the configuration 3), when the thrust disk portion (21) receives a thrust force and is positioned on the one side of the axial intermediate position, a throat can be formed by the one-side fin (81) provided in the portion including the throat-forming position. By providing the one-side fin (81) in the portion including the throat-forming position, damage to the thrust disk portion (21) and the one-side fin (81) can be reduced even if the thrust disk portion (21) comes into contact with the one-side fin (81).

[0082] 4) In some embodiments, the rotary machine (1) according to 1) or 2) above, The one-side throat forming portion (8) includes an opposing surface (56A) provided in a portion including a throat forming position and opposing the one-side thrust bearing (6) with the outer periphery-side flow path (503) interposed therebetween.

[0083] According to the configuration 4), when the thrust disk portion 21 receives a thrust force and is positioned on the one side of the axial center position, the opposing surface 56A provided in the portion including the throat-forming position can form a throat. In this case, the structure can be simplified compared to when the one-side throat-forming portion 8 includes the one-side fin 81.

[0084] 5) In some embodiments, the rotary machine (1) described in 3) above, The one-side fin (81) is When the thrust disk portion (21) is positioned on the one side of the intermediate position in the axial direction, the outer peripheral surface of the thrust disk portion (21) overlaps with the outer peripheral surface of the thrust disk portion (21) in the axial direction, and The bearing is provided at a position that does not overlap with the outer peripheral surface of the thrust disk portion (21) in the axial direction when the thrust disk portion (21) is located at the intermediate position in the axial direction.

[0085] According to the configuration 5) above, when the thrust disk portion (21) is positioned at the middle position in the axial direction or on the other side of the middle position, it is possible to prevent the flow path area formed between the one-side fin (81) and the outer peripheral surface of the thrust disk portion (21) from becoming smaller, and thus it is possible to prevent the one-side fin (81) from obstructing the flow of cooling gas.

[0086] 6) In some embodiments, the rotary machine (1) according to 3) or 5) above, The at least one one-side fin (81) a first one-side fin (81A); and a second one-side fin (81B) provided at a position shifted from the first one-side fin (81A) in the axial direction.

[0087] According to the above configuration 6), by providing two one-side fins (81A, 81B) at positions offset in the axial direction, a throat can be formed in the appropriate one-side fin (81A, 81B) depending on the axial position of the thrust disk portion (21).

[0088] 7) In some embodiments, the rotary machine (1) according to any one of 1) to 6) above, The portion of the one-side throat forming portion (8) including the throat forming position is formed in a circumferential range of at least one-quarter of the circumference of the rotary shaft (2).

[0089] According to the above configuration 7), the one-side throat forming portion (8) is provided over a relatively wide area in the circumferential direction, thereby effectively increasing the static pressure in the one-side flow path (501).

[0090] 8) In some embodiments, the rotary machine (1) according to any one of 1) to 7) above, a cooling gas discharge line (12) for discharging the cooling gas from the outer periphery side flow path (503) to the outside of the casing (5); The cooling gas discharge line (12) The exhaust gas passage includes a discharge-side inlet opening (122) formed in an outer peripheral wall surface (56) that defines a part of the outer side of the outer peripheral flow path (503) in the radial direction.

[0091] According to the above configuration 8), the cooling gas can be introduced into the cooling gas discharge line (12) through the discharge inlet opening (122) formed in the outer peripheral wall surface (56).

[0092] 9) In some embodiments, the rotary machine (1) according to any one of 1) to 7) above, a cooling gas discharge line (12) for discharging the cooling gas from the outer periphery side flow path (503) to the outside of the casing (5); The cooling gas discharge line (12) The thrust disk portion (21) includes a discharge side inlet opening (125) formed on the outer peripheral surface (22).

[0093] According to the configuration 9), the cooling gas can be introduced into the thrust disk portion 21 through the discharge-side inlet opening 125. By circulating the cooling gas inside the thrust disk portion 21, the thrust disk portion 21, the one-side thrust bearing 6, and the other-side thrust bearing 7 can be effectively cooled.

[0094] 10) In some embodiments, the rotary machine (1) described in 9) above, The cooling gas discharge line (12) The rotating shaft (2) includes a discharge side outlet opening (126) formed in the end surface on the one side or the other side.

[0095] According to the above configuration 10), the cooling gas can be discharged to the gas flow path through the discharge outlet opening (126).

[0096] 11) In some embodiments, the rotary machine (1) according to any one of 1) to 10) above, The one-side impeller (3) is a compressor impeller configured to compress gas, The rotary machine (1) comprises: a cooler (302) for cooling the gas compressed by the compressor impeller; At least one cooling gas introduction line (11) is provided, which is configured to introduce the gas cooled by the cooler (302) into at least one of the one-side flow path (501) or the other-side flow path (502) from the inside in the radial direction.

[0097] According to the configuration 11), the gas flowing through the cooling gas introduction line 11 can be pressurized by the compressor impeller 3, which can be used in place of the blower 103. In addition, the gas flowing through the cooling gas introduction line 11 is cooled by the cooler 302, which can effectively cool the one-side thrust bearing 6 and the other-side thrust bearing 7.

[0098] 12) In some embodiments, the rotary machine (1) described in 12) above, a second-side impeller attached to the second side of the rotary shaft in the axial direction, the second-side impeller being a turbine rotor configured to be rotated by the gas cooled by the cooler; a rotor of an electric motor including a permanent magnet and attached to the rotary shaft on the one side of the thrust disk portion (21); a stator of the electric motor including a stationary coil portion and disposed on an outer circumferential side of the rotor to face the rotor with a radial gap therebetween, The at least one cooling gas introduction line (11) a one-side cooled gas introduction line (13) configured to introduce the gas cooled by the cooler into the one-side flow path (501); and an other-side cooling gas introduction line (14) configured to introduce the gas cooled by the cooler into the other-side flow path (502).

[0099] According to the configuration 12), the gas flowing through the one-side cooling gas introduction line 13 and the other-side cooling gas introduction line 14 is cooled by the cooler 302, and therefore the one-side thrust bearing 6 and the other-side thrust bearing 7 can be effectively cooled. In addition, the gas flowing through the one-side cooling gas introduction line 13 can cool the components constituting the electric motor 20.

[0100] 13) In some embodiments, the rotary machine (1) according to 11) or 12) above, a second impeller (4) attached to the second side of the rotary shaft in the axial direction, the second impeller (4) being a turbine rotor configured to be rotated by the gas cooled by the cooler (302); a gas introduction line (301B) for introducing the gas that has passed through the other-side impeller to the one-side impeller; and a cooling gas discharge line (12) for discharging the cooling gas from the outer periphery side flow path (503) to the outside of the casing, the cooling gas discharge line (12) being connected to the gas introduction line (301B).

[0101] If the pressure increase by the compressor impeller (3) is increased, the thrust force acting on the rotary machine (1) increases accordingly, which may result in a decrease in the axial reliability of the rotary machine (1). According to the configuration of 13), if the pressure increase by the compressor impeller (3) is increased, the pressure of the gas flowing through the one-side cooling gas introduction line (13) and the other-side cooling gas introduction line (14) increases accordingly, and the static pressure of the one-side flow path (501) and the other-side flow path (502) can also be increased. This ensures the axial reliability of the rotary machine (1). [Explanation of symbols]

[0102] 1 Rotating Machinery 2 rotating shafts 3 One-side impeller 4 Impeller on the other side 5 Casing 6 One-side thrust bearing 7 Other side thrust bearing 8 One-side throat forming part 9. Other side throat forming part 21 Thrust disk section

Claims

1. A rotating shaft; a one-side impeller attached to one side of the rotary shaft in the axial direction; a thrust disk portion provided on the rotary shaft and extending along a radial direction of the rotary shaft; a casing configured to rotatably accommodate the rotating shaft and the thrust disk portion, the casing including: a one-side flow passage formed between an end face on one side in the axial direction of the thrust disk portion and the casing; a second-side flow passage formed between an end face on the other side in the axial direction of the thrust disk portion and the casing; and an outer circumferential side flow passage connected to outer sides of the one-side flow passage and the second-side flow passage in the radial direction; a one-side thrust bearing that is a gas bearing disposed in the one-side flow path; a second-side thrust bearing that is a gas bearing disposed in the second-side flow path; a one-side throat forming portion that is provided in the outer periphery-side flow passage and that forms a throat having a flow passage area smaller than that of the one-side flow passage between the outer periphery of the thrust disk portion and the one-side throat forming portion when the thrust disk portion is positioned on the one side of the intermediate position in the axial direction, Rotating machinery.

2. a second-side throat forming portion that is provided in the outer circumferential flow path and that forms a throat having a flow path area smaller than that of the second-side flow path between the outer circumferential surface of the thrust disk portion and the second-side throat forming portion when the thrust disk portion is positioned on the second side of the intermediate position in the axial direction, The rotary machine according to claim 1 .

3. the casing has opposing surfaces that face the one-side thrust bearing and the other-side thrust bearing with the outer periphery-side flow path interposed therebetween, the one-side throat forming portion is provided in a portion including a throat forming position and includes at least one one-side fin that protrudes toward an inner side in the radial direction beyond the opposing surface, The rotary machine according to claim 1 or 2.

4. the one-side throat forming portion includes an opposing surface that is provided in a portion including a throat forming position and that faces the one-side thrust bearing and the other-side thrust bearing with the outer periphery-side flow path interposed therebetween, The rotary machine according to claim 1 or 2.

5. The one side fin is When the thrust disk portion is positioned on the one side of the intermediate position in the axial direction, the outer peripheral surface of the thrust disk portion overlaps with the outer peripheral surface of the thrust disk portion in the axial direction, the thrust disk portion is provided at a position where it does not overlap with the outer peripheral surface of the thrust disk portion in the axial direction when the thrust disk portion is located at the intermediate position in the axial direction, The rotary machine according to claim 3 .

6. The at least one lateral fin is a first one-side fin; a second one-side fin provided at a position shifted from the first one-side fin in the axial direction, The rotary machine according to claim 3 .

7. a portion including a throat forming position of the one-side throat forming portion formed in a circumferential range of at least one-quarter of the circumference of the rotary shaft; The rotary machine according to claim 1 or 2.

8. a cooling gas discharge line for discharging the cooling gas from the outer periphery-side flow path to the outside of the casing; The cooling gas discharge line is a discharge-side inlet opening formed in an outer peripheral wall surface that defines a part of the outer peripheral side flow path in the radial direction, The rotary machine according to claim 1 or 2.

9. a cooling gas discharge line for discharging the cooling gas from the outer periphery-side flow path to the outside of the casing; The cooling gas discharge line is a discharge side inlet opening formed on the outer peripheral surface of the thrust disk portion; The rotary machine according to claim 1 or 2.

10. The cooling gas discharge line is a discharge-side outlet opening formed in an end surface of the rotary shaft on the one side or the other side, The rotary machine according to claim 9.

11. The one-side impeller is a compressor impeller configured to compress gas, The rotary machine includes: a cooler for cooling the gas compressed by the compressor impeller; at least one cooling gas introduction line configured to introduce the gas cooled by the cooler into at least one of the one-side flow path or the other-side flow path from an inner side in the radial direction; The rotary machine according to claim 1 or 2.

12. a second-side impeller attached to the second side of the rotary shaft in the axial direction, the second-side impeller being a turbine rotor configured to be rotated by the gas cooled by the cooler; a rotor of an electric motor including a permanent magnet and attached to the rotary shaft on the one side of the thrust disk portion; a stator of the electric motor including a stationary coil portion and disposed on an outer circumferential side of the rotor to face the rotor with a radial gap therebetween, The at least one cooling gas introduction line a one-side cooling gas introduction line configured to introduce the gas cooled by the cooler into the one-side flow path; a second-side cooling gas introduction line configured to introduce the gas cooled by the cooler into the second-side flow path, The rotary machine of claim 11.

13. a second-side impeller attached to the second side of the rotary shaft in the axial direction, the second-side impeller being a turbine rotor configured to be rotated by the gas cooled by the cooler; a gas introduction line for guiding the gas that has passed through the other-side impeller to the one-side impeller; a cooling gas discharge line for discharging the cooling gas from the outer periphery-side flow path to the outside of the casing, the cooling gas discharge line being connected to the gas introduction line; The rotary machine of claim 11.

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