Rotating device

Abstract

A rotating device (C1) is provided with: an impeller (9); a plurality of blades (50) positioned on the outside in the radial direction of the impeller (9) and arranged in the circumferential direction; a housing main body (43) surrounding the impeller (9); a shroud assembly (42) that is separate from the housing main body (43), includes at least a portion of a shroud (41) facing the blade surface of the impeller (9), and is in contact with or fixed to at least a portion of each blade (50); a surface (11b) facing the shroud assembly (42) across the plurality of blades (50); and an elastic member (60) that is disposed between the housing main body (43) and the shroud assembly (42) and that presses the shroud assembly (42) and the blade (50) against the surface (11b).

Description

Technical Field

[0001] The present disclosure relates to a rotating device. This application claims the benefit of priority based on Japanese Patent Application No. 2023-079608, filed on May 12, 2023, the contents of which are incorporated herein by reference. Background Art

[0002] Rotating devices such as centrifugal compressors and turbines sometimes have multiple blades in the flow path around the impeller. For example, Patent Document 1 discloses a centrifugal compressor having multiple diffusion blades. The centrifugal compressor includes a scroll part, a diffusion ring, multiple diffusion blades, and a bearing seat. The diffusion blades are formed integrally with the diffusion ring. The diffusion ring is opposite to the bearing seat via the diffusion blades. In addition, the diffusion ring is fixed to the scroll part. An O-ring is inserted between the diffusion ring and the scroll part. The diffusion blades are pressed against the bearing seat by the stress of the O-ring. According to such a structure, it is possible to suppress the generation of a gap between the bearing seat and the diffusion blades due to the deformation of the scroll part.

[0003] Patent Document 2 discloses a radial turbine equipped with multiple nozzle vanes. This radial turbine comprises a pair of opposing sidewalls, multiple nozzle vanes, and a flange. The nozzle vanes are fixed to the flange. The nozzle vanes and flange are positioned between the pair of sidewalls. A sealing plate is positioned between the flange and one sidewall. The sealing plate presses the nozzle vanes against the other sidewall. This structure reduces the gap between the nozzle vanes and the sidewalls.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Utility Model Application Laid-Open No. 1-91100

[0007] Patent Document 2: Japanese Patent Application Laid-Open No. 61-85503 Summary of the Invention

[0008] Problems to be solved by the invention

[0009] In order to suppress a decrease in efficiency in the above-described rotating device, it is desirable to suppress expansion of the gap between the outermost diameter portion of the impeller and the shroud.

[0010] An object of the present disclosure is to provide a rotating device capable of suppressing expansion of a gap between an outermost diameter portion of an impeller and a shroud.

[0011] Solutions to Problems

[0012] In order to solve the above-mentioned problems, a rotating device of one embodiment of the present invention comprises: an impeller; a plurality of blades, which are located radially outside the impeller and arranged in a circumferential direction; a casing body, which surrounds the impeller; a shroud assembly, which is separate from the casing body and includes at least a portion of the shroud facing the blades of the impeller and is in contact with or fixed to at least a portion of each blade; a surface, which is opposite to the shroud assembly via a plurality of blades; and an elastic component, which is arranged between the casing body and the shroud assembly, and presses the shroud assembly and the blades against the above-mentioned surface.

[0013] The elastic member may include a disc spring disposed around the central axis of the impeller. The disc spring may be disposed radially outward from the outermost diameter portion of the impeller. The inner edge of the disc spring may press the shroud assembly.

[0014] Alternatively, the disc spring may be arranged radially inward of the outermost diameter portion of the impeller, and the outer edge of the disc spring may press the shroud assembly.

[0015] Alternatively, the disc spring may overlap with the outermost diameter portion of the impeller in the radial direction, or the inner edge or the outer edge of the disc spring closer to the outermost diameter portion of the impeller may press the shroud assembly.

[0016] The shroud assembly may also be in contact with or secured to the entire blade.

[0017] The shroud assembly may also terminate at a location radially between the innermost and outermost ends of the blades.

[0018] Effects of the Invention

[0019] According to the present disclosure, it is possible to suppress expansion of the gap between the outermost diameter portion of the impeller and the shroud. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic cross-sectional view of a supercharger including a centrifugal compressor according to the first embodiment.

[0021] Figure 2 Yes Figure 1 A schematic enlarged cross-sectional view of part A in FIG.

[0022] Figure 3 It is a schematic enlarged cross-sectional view showing a modified example.

[0023] Figure 4 It is a schematic enlarged cross-sectional view showing another modified example.

[0024] Figure 5 It is a schematic cross-sectional view of a supercharger including a centrifugal compressor according to a second embodiment.

[0025] Figure 6 Yes Figure 5A schematic enlarged cross-sectional view of part B in FIG. DETAILED DESCRIPTION

[0026] The following describes embodiments of the present disclosure in detail with reference to the accompanying drawings. The specific dimensions, materials, and numerical values ​​shown in these embodiments are merely illustrative for ease of understanding and, unless otherwise noted, do not limit the present disclosure. Furthermore, in this specification and the accompanying drawings, elements having substantially the same function or structure are designated with the same reference numerals to avoid repeated description. Elements not directly related to the present disclosure are omitted from illustration.

[0027] Figure 1 This is a schematic cross-sectional view of a supercharger TC equipped with a centrifugal compressor (rotating device) C1 according to the first embodiment. In this embodiment, the structure of the rotating device disclosed herein is applied to the centrifugal compressor C1. For example, the supercharger TC is applied to an engine. The supercharger TC includes a housing 1, a shaft 7, a turbine impeller 8, and a compressor impeller 9.

[0028] As described later, the turbine impeller 8 and the compressor impeller 9 are arranged concentrically with the shaft 7 and rotate integrally with the shaft 7. Therefore, in this disclosure, the axial direction, radial direction, and circumferential direction of the shaft 7, the turbine impeller 8, and the compressor impeller 9 may be simply referred to as the "axial direction," the "radial direction," and the "circumferential direction," respectively, unless otherwise indicated. Furthermore, in this disclosure, the central axis of the shaft 7, the turbine impeller 8, and the compressor impeller 9 may be simply referred to as the "central axis," unless otherwise indicated.

[0029] The housing 1 includes a bearing housing 2, a turbine housing 3, and a compressor housing 4. One end of the bearing housing 2 is axially connected to the turbine housing 3 by a fastener 21a, such as a bolt. The other end of the bearing housing 2 is axially connected to the compressor housing 4 by a fastener 21b, such as a bolt.

[0030] The bearing housing 2 includes a bearing hole 22. The bearing hole 22 extends in the axial direction within the bearing housing 2. The bearing hole 22 accommodates bearings 23 and 24. The bearings 23 and 24 rotatably support the shaft 7.

[0031] A turbine impeller 8 is provided at a first end portion of the shaft 7 in the axial direction. The turbine impeller 8 is rotatably housed in the turbine housing 3. A compressor impeller 9 is provided at a second end portion of the shaft 7, opposite to the first end portion in the axial direction. The compressor impeller 9 is rotatably housed in the compressor housing 4. The shaft 7, turbine impeller 8, and compressor impeller 9 rotate integrally with each other.

[0032] The compressor housing 4 includes an air inlet 10 at an end portion on the side opposite to the bearing housing 2 in the axial direction. The air inlet 10 is connected to an air filter (not shown). The bearing housing 2 and the compressor housing 4 define a diffusion flow path 11 therebetween. The diffusion flow path 11 has an annular shape. The diffusion flow path 11 is located radially outside the compressor impeller 9. The diffusion flow path 11 is connected to the air inlet 10 via the compressor impeller 9. The diffusion flow path 11 accommodates a plurality of blades 50. The blades 50 are arranged radially outside the compressor impeller 9. The plurality of blades 50 are arranged along the circumferential direction.

[0033] The compressor housing 4 includes a compressor scroll flow path 12. The compressor scroll flow path 12 is located radially outside the diffuser flow path 11. The compressor scroll flow path 12 communicates with the diffuser flow path 11. The compressor scroll flow path 12 also communicates with an air intake of an engine (not shown).

[0034] The compressor housing 4 includes a shroud 41. The shroud 41 is located radially outward of the compressor impeller 9 and faces the blades of the compressor impeller 9 in the radial and axial directions. A gap is formed between the shroud 41 and the blades of the compressor impeller 9. The shroud 41 has a curved shape that expands radially outward as it moves away from the air inlet 10 in the axial direction.

[0035] A portion of the compressor housing 4 forms a shroud assembly 42. In this embodiment, the remaining portion of the compressor housing 4 forms a housing body 43. In other embodiments, the compressor housing 4 may also include other portions. The shroud assembly 42 is separate from the housing body 43. The shroud assembly 42 is mounted on the housing body 43 (details regarding the shroud assembly 42 and the housing body 43 will be described later).

[0036] In the compressor housing 4, when the compressor impeller 9 rotates, fluid (e.g., air) is drawn into the compressor housing 4 through the air inlet 10. The fluid is accelerated as it passes through the compressor impeller 9. The fluid is pressurized in the diffuser flow path 11 and the compressor vortex flow path 12. The pressurized fluid flows out of the discharge port (not shown) and is guided to the engine's air intake. In this way, the portion including the compressor housing 4 and the compressor impeller 9 functions as a centrifugal compressor C1.

[0037] The turbine housing 3 includes an outlet 13 at its axially opposite end from the bearing housing 2. The outlet 13 is connected to an exhaust gas purification device (not shown). The turbine housing 3 includes a flow path 14. The flow path 14 has an annular shape. The flow path 14 is located radially outward of the turbine impeller 8. The flow path 14 communicates with the outlet 13 via the turbine impeller 8.

[0038] The turbine housing 3 includes a turbine scroll flow path 15. The turbine scroll flow path 15 is located radially outward of the flow path 14. The turbine scroll flow path 15 communicates with the flow path 14. Furthermore, the turbine scroll flow path 15 communicates with a gas inlet (not shown). The gas inlet receives exhaust gas discharged from the exhaust manifold of the engine (not shown).

[0039] In the turbine housing 3, the exhaust gas is guided from the gas inlet to the turbine scroll flow path 15, and then guided to the discharge port 13 via the flow path 14 and the turbine impeller 8. The exhaust gas rotates the turbine impeller 8 when passing through the turbine impeller 8.

[0040] The rotational force of the turbine impeller 8 is transmitted to the compressor impeller 9 via the shaft 7. As the compressor impeller 9 rotates, the fluid is pressurized as described above. The pressurized fluid is then directed to the engine's air intake. Thus, the portion including the turbine housing 3 and the turbine impeller 8 functions as a turbine T.

[0041] Next, the shield assembly 42 and the housing body 43 will be described in detail.

[0042] Figure 2 Yes Figure 1 Schematic enlarged sectional view of portion A in FIG. As described above, the blades 50 are housed in the diffuser flow path 11. The diffuser flow path 11 is defined by the surface (first surface) 11a and the surface (second surface) 11b. In addition, in the present disclosure, "delimitation" may refer to a division or boundary that determines a space such as a flow path or a gap. The surface 11a is defined by the compressor housing 4, and the surface 11b is defined by the bearing housing 2. The surface 11a is continuous with the shroud 41. The surface 11b is opposite to the surface 11a in the axial direction.

[0043] For example, the blade 50 is fixed to one of the surface 11a and the surface 11b. For example, the blade 50 may be fixed to the surface 11a. In this case, the blade 50 contacts the surface 11b. In other embodiments, the blade 50 may be fixed to the surface 11b. In this case, the blade 50 contacts the surface 11a.

[0044] The shroud assembly 42 is located radially outside the impeller 9. The shroud assembly 42 includes at least a portion of the shroud 41. In addition, the shroud assembly 42 includes at least a portion of the surface 11a. That is, the shroud assembly 42 spans the shroud 41 and the diffuser flow path 11 in the radial direction. In this embodiment, the shroud assembly 42 extends radially from at least the leading edge (innermost end) LE to the trailing edge (outermost end) TE of the blade 50. Figure 1 More specifically, in this embodiment, the shroud assembly 42 includes the entire shroud 41. Therefore, the shroud assembly 42 of this embodiment bears at least a portion of the inner circumference of the scroll member. Figure 2The shroud assembly 42 extends radially outward beyond the trailing edge TE. In this embodiment, the shroud assembly 42 encompasses the entire surface 11a. The shroud assembly 42 is fitted into the housing body 43 in a manner that allows the disc springs 60 (described later) to press the shroud assembly 42 and the vanes 50 against the surface 11b. Therefore, a small gap (not shown) may be provided between the shroud assembly 42 and the housing body 43.

[0045] The compressor housing 4 includes a housing chamber 44 between the shroud assembly 42 and the housing body 43. In this embodiment, the housing chamber 44 has a circular ring shape. The housing chamber 44 is defined in the axial direction by surfaces 44a and 44b. Specifically, the shroud assembly 42 includes surface 44a, and the housing body 43 includes surface 44b. In this embodiment, surfaces 44a and 44b are perpendicular to the axial direction. Surfaces 44a and 44b are separated from each other in the axial direction and face each other in the axial direction.

[0046] A disc spring (elastic component) 60 is arranged in the accommodation chamber 44. The disc spring 60 has a roughly truncated cone shape. The disc spring 60 is arranged around the central axis of the compressor impeller 9. The disc spring 60 is arranged concentrically with the compressor impeller 9. The disc spring 60 is clamped by the surface 44a and the surface 44b. The disc spring 60 includes an inner edge 60a and an outer edge 60b. In the present embodiment, the disc spring 60 is located radially outside the outermost diameter portion of the compressor impeller 9. In this case, in the radial direction, the inner edge 60a of the disc spring 60 is closest to the outermost diameter portion of the compressor impeller 9. Therefore, in the present embodiment, the disc spring 60 is arranged so that the inner edge 60a contacts the surface 44a of the shroud assembly 42 and the outer edge 60b contacts the surface 44b of the housing body 43.

[0047] Figure 3 It is a schematic enlarged sectional view showing a modified example. The centrifugal compressor C1a of this example differs from the centrifugal compressor C1 described above in the position of the disc spring 60. With regard to other structures, the centrifugal compressor C1a may be the same as the centrifugal compressor C1. The disc spring 60 is located radially inward of the outermost diameter portion of the compressor impeller 9. In this case, in the radial direction, the outer edge 60b of the disc spring 60 is closest to the outermost diameter portion of the compressor impeller 9. Therefore, the disc spring 60 is configured so that the outer edge 60b contacts the surface 44a of the shroud assembly 42 and the inner edge 60a contacts the surface 44b of the casing body 43.

[0048] Figure 4It is a schematic enlarged sectional view showing another modified example. The centrifugal compressor C1b of this example is different from the centrifugal compressors C1 and C1a described above in the position of the disc spring 60. With regard to other structures, the centrifugal compressor C1b may also be the same as the centrifugal compressors C1 and C1a. The disc spring 60 overlaps with the outermost diameter portion of the compressor impeller 9 in the radial direction. In this case, the disc spring 60 is arranged so that the inner edge 60a and the outer edge 60b, whichever is closer to the outermost diameter portion of the compressor impeller 9, press the surface 44a of the shroud assembly 42. Figure 4 In the example of FIG, the outer edge 60 b is close to the outermost diameter portion of the compressor impeller 9. Therefore, the disc spring 60 is arranged so that the outer edge 60 b presses the surface 44 a of the shroud assembly 42.

[0049] According to the structure of the centrifugal compressors C1, C1a, and C1b as described above, the disc spring 60 can be used to press the position of the shroud assembly 42 closer to the outermost diameter portion of the compressor impeller 9. Therefore, the expansion of the gap between the outermost diameter portion of the compressor impeller 9 and the shroud 41 can be further suppressed. These structures are also applicable to the centrifugal compressor C2 of the second embodiment described later. In addition, the direction of the disc spring 60 can also be opposite to the above-mentioned structure. For example, in Figure 2 In the embodiment, the outer edge 60b may contact the surface 44a of the shroud assembly 42, and the inner edge 60a may contact the surface 44b of the housing body 43. In this case, the shroud assembly 42 can also be pressed by the disc spring 60 so as to approach the compressor impeller 9 in the axial direction.

[0050] During assembly of the supercharger TC, the disc spring 60 is placed in the accommodation chamber 44 in an axially compressed state. The disc spring 60 is preloaded. The inner edge 60a of the disc spring 60 presses the shroud assembly 42 axially toward the surface 11b. Consequently, the shroud assembly 42 is pressed axially toward the compressor impeller 9. The shroud assembly 42 comprises at least a portion of the shroud 41, specifically, the portion of the shroud 41 axially facing the outermost portion of the compressor impeller 9. Therefore, when the compressor housing 4 is thermally deformed by high-temperature fluid, expansion of the gap between the shroud 41 and the outermost portion of the compressor impeller 9 is suppressed. Furthermore, the inner edge 60a of the disc spring 60, together with the shroud assembly 42, presses the blade 50 axially toward the surface 11b. This suppresses expansion of the gap between the blade 50 and the surface 11b, or between the blade 50 and the surface 11a. Consequently, a decrease in the efficiency of the centrifugal compressor C1 can be minimized.

[0051] The centrifugal compressor C1 described above includes: a compressor impeller 9; a plurality of blades 50 located radially outward of the compressor impeller 9 and arranged circumferentially; a housing body 43 surrounding the compressor impeller 9; a shroud assembly 42 separate from the housing body 43, including at least a portion of a shroud 41 facing the blade surface of the compressor impeller 9 and in contact with or fixed to at least a portion of each blade 50; a surface (opposite surface) 11b facing the shroud assembly 42 with the plurality of blades 50 interposed therebetween; and a disc spring 60 disposed between the housing body 43 and the shroud assembly 42, pressing the shroud assembly 42 and the blades 50 toward the surface 11b. With this configuration, the shroud assembly 42 is pressed axially toward the compressor impeller 9 by the disc spring 60. Therefore, when the compressor housing 4 thermally deforms, expansion of the gap between the shroud 41 and the outermost diameter portion of the compressor impeller 9 is suppressed. Furthermore, according to the above-described structure, the blade 50 and the shroud assembly 42 are pressed toward the surface 11b by the disc spring 60, thereby suppressing the expansion of the gap between the blade 50 and the surface 11b or the gap between the blade 50 and the surface 11a. Therefore, it is possible to suppress a decrease in the efficiency of the centrifugal compressor C1.

[0052] Furthermore, in the centrifugal compressor C1, the shroud assembly 42 is in contact with or fixed to the entire blade 50. With such a structure, the entire blade 50 is pressed by the shroud assembly 42. Therefore, local deformation of the blade 50 can be reduced.

[0053] In centrifugal compressor C1, the elastic member includes a disc spring 60 arranged around the central axis of the compressor impeller 9. The disc spring 60 is positioned radially outward from the outermost diameter portion of the compressor impeller 9, and the inner edge 60a of the disc spring 60 presses the shroud assembly 42. Furthermore, in centrifugal compressor C1a, the disc spring 60 is positioned radially inward from the outermost diameter portion of the compressor impeller 9, and the outer edge 60b of the disc spring 60 presses the shroud assembly 42. Furthermore, in centrifugal compressor C1b, the disc spring 60 radially overlaps the outermost diameter portion of the compressor impeller 9, and the inner edge 60a or outer edge 60b closer to the outermost diameter portion of the compressor impeller 9 presses the shroud assembly 42. These configurations allow the disc spring 60 to press the shroud assembly 42 at a location closer to the outermost diameter portion of the compressor impeller 9. Consequently, expansion of the gap between the outermost diameter portion of the compressor impeller 9 and the shroud 41 can be further suppressed.

[0054] Next, other embodiments will be described.

[0055] Figure 5This is a schematic cross-sectional view of a supercharger TC equipped with a centrifugal compressor C2 according to a second embodiment. The centrifugal compressor C2 differs from the centrifugal compressor C1 according to the first embodiment in the shape of the shroud assembly 42. In other configurations, the centrifugal compressor C2 may be similar to the centrifugal compressor C1.

[0056] Figure 6 Yes Figure 5 In this embodiment, the shroud assembly 42 ends at a position P between the leading edge LE and the trailing edge TE in the radial direction. Figure 5 as well as Figure 6 Specifically, in this embodiment, the shield assembly 42 includes an area from a portion of the shield 41 that is parallel to the central axis to a position P between the leading edge LE and the trailing edge TE. Figure 6 In the present embodiment, the shroud assembly 42 does not include the surface 11 a except for the portion radially outward from the position P.

[0057] Reference Figure 1 In the centrifugal compressor C1 of the first embodiment, the shroud assembly 42 extends longer in the radial direction, so the upstream boundary W and the downstream boundary X between the shroud assembly 42 and the casing body 43 are separated from each other by a large distance. Figure 5 In the centrifugal compressor C2 of the second embodiment, the shroud assembly 42 is shorter in the radial direction, so the upstream boundary Y and the downstream boundary Z between the shroud assembly 42 and the casing body 43 are closer. This structure can reduce the pressure difference between the boundary Y and the boundary Z, thereby reducing fluid leakage.

[0058] The centrifugal compressor C2 described above achieves substantially the same effects as the centrifugal compressor C1 of the first embodiment. Furthermore, in the centrifugal compressor C2, the shroud assembly 42 terminates at position P radially between the leading edge LE and the trailing edge TE. This configuration shortens the shroud assembly 42 radially, reducing the pressure difference between the boundary Y and the boundary Z, as described above, and thereby reducing fluid leakage.

[0059] The above embodiments are described with reference to the accompanying drawings, but the present disclosure is not limited to the above embodiments. It should be understood that those skilled in the art can obviously think of various changes or modifications within the scope of the claims, which also fall within the technical scope of the present disclosure.

[0060] For example, in the above-mentioned embodiment, a disc spring is used as the elastic member. In other embodiments, various elastic members such as a coil spring or a heat-resistant resin may be used.

[0061] In the above-described embodiment, the rotary device of the present disclosure is applied to centrifugal compressors C1 and C2. In other embodiments, for example, the turbine T may include nozzle vanes (not shown) in the flow path 14, and the rotary device of the present disclosure may also be applied to a turbine T including a turbine wheel 8, nozzle vanes, and a turbine housing 3.

[0062] Explanation of symbols

[0063] 8—turbine impeller, 9—compressor impeller, 11b—surface opposite to the shroud assembly, 41—shroud, 42—shroud assembly, 43—casing body, 50—blade, 60—disc spring (elastic component), 60a—inner edge of disc spring, 60b—outer edge of disc spring, C1—centrifugal compressor (rotating device), C1a—centrifugal compressor (rotating device), C1b—centrifugal compressor (rotating device), C2—centrifugal compressor (rotating device), LE—leading edge (innermost end of the blade), P—position between the leading edge and the trailing edge, T—turbine (rotating device), TE—trailing edge (outermost end of the blade).

Claims

1. A rotating device, characterized in that: have: impeller; a plurality of blades located radially outside the impeller and arranged along the circumferential direction; a casing body surrounding the impeller; a shroud assembly, which is separate from the casing body and includes at least a portion of the shroud facing the blades of the impeller and in contact with or fixed to at least a portion of each blade; a surface opposing the shroud assembly across the plurality of blades; as well as An elastic member is disposed between the housing body and the shroud assembly and presses the shroud assembly and the blades toward the surface.

2. The rotating device according to claim 1, characterized in that The elastic component includes a disc spring arranged around the central axis of the impeller, The disc spring is arranged radially outward of the outermost diameter portion of the impeller, and an inner edge of the disc spring presses the shroud assembly.

3. The rotating device according to claim 1, characterized in that The elastic component includes a disc spring arranged around the central axis of the impeller, The disc spring is arranged radially inward of an outermost diameter portion of the impeller, and an outer edge of the disc spring presses the shroud assembly.

4. The rotating device according to claim 1, characterized in that The elastic component includes a disc spring arranged around the central axis of the impeller, The disc spring overlaps with the outermost diameter portion of the impeller in the radial direction, and one of the inner edge and the outer edge of the disc spring closer to the outermost diameter portion of the impeller presses the shroud assembly.

5. The rotating device according to any one of claims 1 to 4, characterized in that: The shroud assembly contacts or is fixed to the entire blade.

6. The rotating device according to any one of claims 1 to 4, characterized in that: The shroud assembly terminates radially between the innermost and outermost ends of the blades.

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