Abstract: A centrifugal compressor 10 includes a diffuser 13 that comprises: a shroud wall surface 131 that extends in the radial direction of a rotating shaft 3; and a hub wall surface 132 that extends in the radial direction and opposes the shroud wall surface 131 on the downstream side of a flow in the axial direction of the rotating shaft 3, the hub wall surface having a gap between itself and the shroud wall surface 131, and with that gap, forming an annular diffuser flow path 130 through which a fluid flows. A hub-side convex portion 132b is formed over the entire periphery of the hub wall surface 132, the hub-side convex portion 132b protruding toward the shroud wall surface 131 side relative to a straight line L1 that connects a starting end 132s on an inlet 130a side of the diffuser flow path 130 and a terminating end 132e on an outlet 130b side of the diffuser flow path 130.

Abstract: A centrifugal compressor includes an impeller, a diffuser flow passage forming portion forming an annular diffuser flow passage on a downstream side of the impeller, a plurality of small chord-pitch ratio diffuser blades disposed in the diffuser flow passage at intervals in a circumferential direction of the impeller, and a flow passage dividing annulus extending to the diffuser flow passage along a radial direction of the impeller, and dividing the diffuser flow passage into a hub-side flow passage and a shroud-side flow passage.

Abstract: A gas expander includes: a casing where a swirl chamber for a gas to be expanded is formed; a turbine wheel that is housed in the casing and rotationally driven by the expanded gas; a diffuser that is mounted to the casing in a direction of a rotating shaft of the turbine wheel and includes a flow path for the expanded gas to flow in the direction of the rotating shaft; a swirl stopper that is disposed in the diffuser, faces a downstream front end surface of a boss of the turbine wheel that faces the flow path, and includes a closed swirl stopping surface that is disposed to face the downstream front end surface of the boss with a gap between the closed swirl stopping surface and the downstream front end surface; and a swirl preventing plate that circumferentially partition the flow path in the diffuser.

Abstract: A centrifugal compressor 10 includes a diffuser 13 that comprises: a shroud wall surface 131 that extends in the radial direction of a rotating shaft 3; and a hub wall surface 132 that extends in the radial direction and opposes the shroud wall surface 131 on the downstream side of a flow in the axial direction of the rotating shaft 3, the hub wall surface having a gap between itself and the shroud wall surface 131, and with that gap, forming an annular diffuser flow path 130 through which a fluid flows. A hub-side convex portion 132b is formed over the entire periphery of the hub wall surface 132, the hub-side convex portion 132b protruding toward the shroud wall surface 131 side relative to a straight line L1 that connects a starting end 132s on an inlet 130a side of the diffuser flow path 130 and a terminating end 132e on an outlet 130b side of the diffuser flow path 130.

Abstract: A turbocharger is provided with a valve body which is disposed in a suction flow path (Cb) leading from an inflow port of a housing covering a turbine rotor blade to a scroll flow path (Ca) and composed of a single piece or multiple divided pieces to supply a fluid (G) to the turbine rotor blade with the inner surface thereof formed using a first wall surface and a second wall surface facing the first wall surface as part thereof, extends from the upstream side to the downstream side of the flow of the fluid (G), is rotatably provided in the housing in a direction toward and away from the first wall surface and the second wall surface, forms an upstream-side narrowed flow path (F1) with the first wall surface therebetween at an end on the upstream side, and forms a downstream-side narrowed flow path (F2) with the second wall surface therebetween at an end on the downstream side.

Abstract: A turbocharger is provided with a valve body which is disposed in a suction flow path leading from an inflow port of a housing covering a turbine rotor blade to a scroll portion and composed of a single piece or multiple divided pieces to supply a fluid to the turbine rotor blade with the inner surface thereof formed using a first wall surface and a second wall surface facing the first wall surface as part thereof, extends from the upstream side to the downstream side of the flow of the fluid, is rotatably provided in the housing in a direction toward and away from the first wall surface and the second wall surface, forms an upstream-side narrowed flow path with the first wall surface therebetween at an end on the upstream side, and forms a downstream-side narrowed flow path with the second wall surface therebetween at an end on the downstream side.

Abstract: A centrifugal compressor includes an impeller, a diffuser flow passage forming portion forming an annular diffuser flow passage on a downstream side of the impeller, a plurality of small chord-pitch ratio diffuser blades disposed in the diffuser flow passage at intervals in a circumferential direction of the impeller, and a flow passage dividing annulus extending to the diffuser flow passage along a radial direction of the impeller, and dividing the diffuser flow passage into a hub-side flow passage and a shroud-side flow passage.

Abstract: A gas expander includes: a casing where a swirl chamber for a gas to be expanded is formed; a turbine wheel that is housed in the casing and rotationally driven by the expanded gas; a diffuser that is mounted to the casing in a direction of a rotating shaft of the turbine wheel and includes a flow path for the expanded gas to flow in the direction of the rotating shaft; a swirl stopper that is disposed in the diffuser, faces a downstream front end surface of a boss of the turbine wheel that faces the flow path, and includes a closed swirl stopping surface that is disposed to face the downstream front end surface of the boss with a gap between the closed swirl stopping surface and the downstream front end surface; and a swirl preventing plate that circumferentially partition the flow path in the diffuser.

Abstract: An object is to provide a sheet-metal turbine housing reinforced by a readily-manufacturable structure, the sheet-metal turbine housing also having a small thickness and improved containment performance. A sheet-metal turbine housing includes: a scroll part forming an exhaust gas channel of a scroll shape in a turbocharger for driving a turbine with exhaust gas of an engine, the scroll part comprising sheet metal; and at least one rib portion of a protrusion shape formed on an outer wall surface of the scroll part at a radially outer side of an inlet edge of a turbine blade along a circumferential direction of the scroll part, the at least one rib portion protruding either outward or inward, or both, and including a bend and bend-back structure formed on the sheet metal forming the scroll part.

Abstract: In a turbine rotor blade of a radial turbine, especially in a variable-geometry turbine with variable nozzles, an object is to restrict high-order resonance of the turbine rotor blade without increasing the size of a device with a simplified structure. A plurality of turbine rotor blades for a radial turbine is disposed on a hub surface. Each turbine rotor blade includes blade-thickness changing portions, at which at least a blade thickness of a cross-sectional shape at a middle portion of a blade height increases rapidly with respect to a blade thickness of a leading-edge side, at a predetermined position from a leading edge along a blade length which follows a gas flow from the leading edge to a trailing edge. The blade thickness increases to a blade thickness via the blade-thickness changing portions.

Abstract: A turbocharger is provided with a valve body which is disposed in a suction flow path (Cb) leading from an inflow port of a housing covering a turbine rotor blade to a scroll flow path (Ca) and composed of a single piece or multiple divided pieces to supply a fluid (G) to the turbine rotor blade with the inner surface thereof formed using a first wall surface and a second wall surface facing the first wall surface as part thereof, extends from the upstream side to the downstream side of the flow of the fluid (G), is rotatably provided in the housing in a direction toward and away from the first wall surface and the second wall surface, forms an upstream-side narrowed flow path (F1) with the first wall surface therebetween at an end on the upstream side, and forms a downstream-side narrowed flow path (F2) with the second wall surface therebetween at an end on the downstream side.

Abstract: A turbocharger is provided with a valve body which is disposed in a suction flow path leading from an inflow port of a housing covering a turbine rotor blade to a scroll portion and composed of a single piece or multiple divided pieces to supply a fluid to the turbine rotor blade with the inner surface thereof formed using a first wall surface and a second wall surface facing the first wall surface as part thereof, extends from the upstream side to the downstream side of the flow of the fluid, is rotatably provided in the housing in a direction toward and away from the first wall surface and the second wall surface, forms an upstream-side narrowed flow path with the first wall surface therebetween at an end on the upstream side, and forms a downstream-side narrowed flow path with the second wall surface therebetween at an end on the downstream side.

Abstract: An object is to provide a mixed flow turbine, wherein intermediate blades having an intermediate height are provided between main blades of the mixed flow turbine, thus improving an impulse blade turbine characteristic and reducing the moment of inertia for a rotor blade as a whole, thereby improving the efficiency and transient response.

Abstract: A multi-pressure radial turbine system including a high-pressure pump and a low-pressure pump for pressurizing liquid-phase heating media introduced therein to different pressures; a high-pressure evaporator and a low-pressure evaporator for vaporizing the liquid-phase heating media delivered from the high-pressure pump and the low-pressure pump by absorbing heat from a high-temperature heat source; one multi-pressure radial turbine that expands the gaseous heating media having different pressures and temperatures, supplied from the high-pressure evaporator and the low-pressure evaporator, to obtain output power; and a condenser for condensing the gaseous heating medium expanded in the multi-pressure radial turbine by making the medium release heat to a low-pressure heat source. A cycle circuit is formed through which the heating medium circulates while repeatedly changing its state between vapor and liquid.

Abstract: An object is to provide a sheet-metal turbine housing reinforced by a readily-manufacturable structure, the sheet-metal turbine housing also having a small thickness and improved containment performance. A sheet-metal turbine housing includes: a scroll part forming an exhaust gas channel of a scroll shape in a turbocharger for driving a turbine with exhaust gas of an engine, the scroll part comprising sheet metal; and at least one rib portion of a protrusion shape formed on an outer wall surface of the scroll part at a radially outer side of an inlet edge of a turbine blade along a circumferential direction of the scroll part, the at least one rib portion protruding either outward or inward, or both, and including a bend and bend-back structure formed on the sheet metal forming the scroll part.

Abstract: In a turbine rotor blade of a radial turbine, especially in a variable-geometry turbine with variable nozzles, an object is to restrict high-order resonance of the turbine rotor blade without increasing the size of a device with a simplified structure. A plurality of turbine rotor blades for a radial turbine is disposed on a hub surface. Each turbine rotor blade includes blade-thickness changing portions, at which at least a blade thickness of a cross-sectional shape at a middle portion of a blade height increases rapidly with respect to a blade thickness of a leading-edge side, at a predetermined position from a leading edge along a blade length which follows a gas flow from the leading edge to a trailing edge. The blade thickness increases to a blade thickness via the blade-thickness changing portions.

Abstract: An object is to provide a mixed flow turbine, wherein intermediate blades having an intermediate height are provided between main blades of the mixed flow turbine, thus improving an impulse blade turbine characteristic and reducing the moment of inertia for a rotor blade as a whole, thereby improving the efficiency and transient response.

Abstract: Provided is a uni-axial multi-stage radial gas expander which has a high degree of reliability and which can sufficiently cope with the conditions of a high pressure and a high pressure ratio. Two or more radial gas expander sections (11A, 11B) formed of two-or-more-stage impeller vanes (14a to 14h) arranged between bearings (21a, 21b) on a rotor shaft (13) consisting of a single shaft are housed in a signal casing (10).

Abstract: A radial turbine includes a radial turbine wheel provided with a main pathway in which blade height progressively increases while curving toward an axial direction from a radial direction. A sub-let is formed on a shroud side of the radial turbine wheel at a position separated from the main inlet in the radial direction and the axial direction. Also, a blade shape that forms the sub-inlet is such that, in a plane orthogonal to the axial line of the radial turbine wheel, a center line of the blade is inclined at a predetermined angle toward the rotation direction with respect to the radial direction.

Abstract: A multi-pressure radial turbine system including a high-pressure pump and a low-pressure pump for pressurizing liquid-phase heating media introduced therein to different pressures; a high-pressure evaporator and a low-pressure evaporator for vaporizing the liquid-phase heating media delivered from the high-pressure pump and the low-pressure pump by absorbing heat from a high-temperature heat source; one multi-pressure radial turbine that expands the gaseous heating media having different pressures and temperatures, supplied from the high-pressure evaporator and the low-pressure evaporator, to obtain output power; and a condenser for condensing the gaseous heating medium expanded in the multi-pressure radial turbine by making the medium release heat to a low-pressure heat source. A cycle circuit is formed through which the heating medium circulates while repeatedly changing its state between vapor and liquid.