Abstract: Suction surfaces of blades of this radial turbine each have: a leading edge side of blade tip including a leading edge and the boundary between the suction surface and the tip; and a trailing edge side of blade tip including a trailing edge and the boundary between the suction surface and the tip. The leading edge side of blade tip forms a concave curved surface which is recessed towards the side opposite to the rotation side in a radial view. The trailing edge side of blade tip forms a convex curved surface which protrudes towards the rotation side in a radial view.

Abstract: An object is to reduce loss of exhaust gas by improving a surface roughness to enhance efficiency of a turbocharger and to reduce generation of a crack due to thermal fatigue to improve durability, as well as to ensure rigidity to prevent exhaust-gas leakage to outside. A turbine housing accommodates a turbine wheel rotated by exhaust gas taken in from an engine and includes a scroll part having a scroll shape and forming, on a radially-inner side, an exhaust-gas flow passage. The turbine housing includes: a casted exterior member forming an opening portion accommodating a back-face member attachable and detachable in an axial direction of the turbine wheel; and a sheet-metal interior member disposed inside the exterior member via a predetermined clearance part from the exterior member and forming the scroll part. The interior member is configured to be attachable and detachable with respect to the exterior member through the opening portion.

Abstract: A radial turbine comprises a plurality of nozzle vanes disposed along a circumferential direction inside a spiral scroll and configured to regulate a flow of a working gas from the scroll to a rotor blade, wherein each of the nozzle vane includes a leading edge bulging portion on both end portions in a width direction of an inlet leading edge portion, the leading edge bulging portion being bulged toward a pressure face side of the nozzle vane relative to a central portion, so that a vane angle is configured to correspond with an inflow angle of the working gas to be flown into the nozzle vane, and wherein each of the nozzle vane includes a trailing edge bulging portion on both end portions in a width direction of an outlet trailing edge portion, the trailing edge bulging portion being bulged toward the pressure face side relative to a central portion, so that an outflow angle of the working gas from the outlet trailing edge of the nozzle vane becomes uniform.

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: A turbine casing includes: a shroud of a cylindrical shape defining an operational flow path between the shroud and a hub of a turbine rotor; a scroll outer peripheral wall continuing from an end side of the shroud and extending along a circumferential direction of the shroud; and a partition wall disposed inside the scroll outer peripheral wall and dividing an inside of the scroll outer peripheral wall into a first scroll flow path and a second scroll flow path disposed adjacent to each other in an axial direction of the shroud. The shroud, the scroll outer peripheral wall, and the partition wall are formed integrally by casting. The partition wall has a widening section which partially increases a communication area between at least two of the first scroll flow path, the second scroll flow path, and the operational flow path, in the circumferential direction of the shroud.

Abstract: A turbocharger device includes: a turbocharger (3); and a turbo controller (35) configured to control a waste-gate valve (31) or a variable-displacement mechanism of an exhaust-gas amount supplied to the turbine to control a boost pressure of the turbocharger, the turbo controller (35) including a control calculation part (44) and a sensor signal input part (45) provided separately and independently from an engine controller (33) and being mounted to a compressor housing at a side of the compressor (23b) of the turbocharger (3).

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 variable-geometry exhaust turbine whereby it is possible to prevent deformation and damage to a nozzle support under a high temperature. A variable-geometry exhaust turbine includes: a nozzle mount, a nozzle support including a first end portion joined to the first surface of the nozzle mount, a nozzle plate including the first surface joined to the second end portion of the nozzle support 6 and supported so as to face the nozzle mount at a distance, and the opposite second surface facing an exhaust—as channel through which exhaust gas flows, and a plurality of nozzle vanes supported rotatably between the nozzle mount and the nozzle plate. The nozzle support is capable of tilting along a radial direction so as to absorb a relative displacement in the radial direction between the nozzle mount and the nozzle plate due to thermal expansion.

Abstract: In a variable geometry turbocharger including a variable nozzle mechanism, an object is to enhance safety upon malfunction of the variable nozzle mechanism as well as to improve accuracy in the control of the variable nozzle mechanism by applying a moment that acts on the nozzle vanes in an opening direction securely and stably.

Abstract: The flow-through characteristics of twin exhaust gas scroll passages of a turbine are made equal to each other. A tongue which partitions the scroll portions into outer peripheral portions and inner peripheral portions includes a front-side tongue and a rear-side tongue that respectively close the two exhaust gas passages at the outer peripheral portion. The inner sides of the front-side tongue and the rear-side tongue, and the minimal outflow width portions of the front-side passage and the rear-side passage, respectively, are formed substantially parallel to each other at a downstream end of the outer peripheral portion.

Abstract: A turbine impeller includes: a hub portion coupled to an end of a rotational shaft; a plurality of main blades disposed at intervals on a peripheral surface of the hub portion; and a short blade disposed between two adjacent main blades among the plurality of main blades. An inter-blade flow channel is formed between the two adjacent main blades so that a fluid flows through the inter-blade flow channel from an outer side toward an inner side of the turbine impeller in a radial direction. In a meridional plane, a hub-side end of a leading edge of the short blade is disposed on an inner side, in the radial direction, of a hub-side end of a leading edge of the main blade.

Abstract: A turbocharger is of reduced size and easy to assemble. A rotor blade upstream flow channel space has a cylindrical portion that is gradually reduced in the downstream direction of exhaust gas flow corresponding with a reduction in volume of the scroll chamber. A back plate is formed so as to swell out toward the rotor blade gradually in the downstream direction corresponding with the reduction in volume of the scroll chamber. The back plate, at a termination end thereof, approaches the rotor blade and reaches a position adjacent to a leading edge of the rotor blade whereby the flow channel space disappears substantially at this termination end.

Abstract: An object is to provide an engine system including an intake bypass device whereby it is possible to expand the operation range of a compressor without causing the output of a turbine to become insufficient. An engine system includes an intake bypass device including a bypass channel connecting a downstream side of a compressor of a turbocharger in an intake channel and an upstream side of a turbine of the turbocharger in an exhaust channel, a bypass valve disposed in the bypass channel and configured to control a flow of compressed intake air in the bypass channel, and a heating unit for heating the compressed intake air flowing through the bypass channel.

Abstract: An object is to provide an air intake duct structure for a centrifugal fluid machine, capable of swirling the fluid introduced into the impeller in the reverse direction to increase the pressure ratio when the flow rate is high and swirling the fluid in the forward direction to avoid a surging when the flow rate is low, as well as securing a wide operating range, without using mechanical means. The centrifugal fluid machine 1 includes an impeller 12 mounted to a rotation shaft and a housing 4 for housing the impeller 12. The air intake duct structure 10 is for directing a fluid “f” to a rotational center 12a of the impeller 12 housed in the housing 4 via an intake duct portion 4a of the housing 4 protruding in an axial direction of the rotation shaft, the fluid “f” flowing in a substantially orthogonal direction to a rotational axis line 3.

Abstract: An object is to provide a radial turbine blade that can reduce an impact loss of inflowing gas at a leading edge of the turbine blade and achieve a higher turbine efficiency, even in a case of a flow field corresponding to a low turbine operational velocity ratio U/C0 due to a throttling operation on a variable nozzle mechanism of a variable geometry turbocharger. In a radial turbine blade, a hub-side end portion Pa at a leading edge 51 of a turbine blade 50 is formed to be positioned more on a rear side in a rotation direction R of the turbine blade 50 than a shroud-side end portion Sc at the leading edge 51, and a straight line connecting between the shroud-side end portion Sc and the hub-side end portion Pa is inclined with respect to a straight line extending in a rotation axis direction from the shroud-side end portion Sc at the leading edge 51 onto a hub 17 surface by an angle in a range from 30° to 70° as viewed in the radial direction of the turbine blade 50.

Abstract: A turbine includes a housing including an inlet, an outlet, and a shroud section having a shroud surface extending between the inlet and the outlet; and a turbine impeller housed in the housing and including a hub and a plurality of blades disposed on an outer peripheral surface of the hub, each of the blades having a side edge extending along the shroud surface. The side edge of each of the blades has a side-edge upstream portion disposed on a side of the inlet, and a side-edge downstream portion disposed on a side of the outlet. The shroud surface has a shroud upstream portion disposed on the side of the inlet and extending along the side-edge upstream portion, and a shroud downstream portion disposed on the side of the outlet and extending along the side-edge downstream portion.

Abstract: An object is to provide a turbine housing with a simple structure whereby it is possible to reduce flow resistance of exhaust gas and improve efficiency of a turbocharger. A turbine housing made by casting has an opening part formed on a hub side of a scroll part, the opening part having a radius R2 which satisfies a relationship R1<R2, provided that R1 is a radial directional distance from an axis of a turbine wheel to a tip of a shroud part and R2 is a radial directional distance from the axis to an inner peripheral edge of a hub-side wall surface of the scroll part. A roughness of a flow-path surface in a region A is smaller than in a region B, provided that the region A is a predetermined range from the tip of the shroud part and the region B is a predetermined range adjacent to the region A, among flow-path surfaces of the shroud part and the scroll part facing a scroll flow path on an outer side, in a radial direction, of the tip of the shroud part.

Abstract: An expansion turbine (10A) includes: a turbine housing (13) including a scroll section for taking in working fluid (w); a plurality of variable nozzles (36) disposed inside the turbine housing at intervals in a circumferential direction of the expansion turbine, each of the variable nozzles being configured to be rotatable about a rotation shaft (38); and a turbine wheel (24) disposed rotatably inside the turbine housing, the turbine wheel including a plurality of turbine blades disposed downstream of the variable nozzles. The turbine housing has a first wall surface (50) including a shroud section which faces tips (28a) of the turbine blades, and a second wall surface (52) which faces the first wall surface across a flow path (f) of the working fluid. A blade height of the variable nozzles at an outlet side is greater than a blade height of the turbine blades at an inlet side.

Abstract: A twin-scroll turbocharger comprises front and rear scrolls, a scroll throat portion separating the scrolls, a rotor blade rotated by exhaust gas, and a turbine housing forming, with an outer circumferential portion of the rotor blade, the front scroll and the rear scroll, and including an inclined surface on which an extended line of the incline facing toward the scroll throat portion of the front scroll and an inlet of the rotor blade intersect at a position in a central portion of the inlet of the rotor blade, wherein the connection R at a crossing portion P where the inclined surface and an inner periphery surface of the turbine housing intersect has a shape such that the gap of a constant width a continues to the position of the inlet of the rotor blade.

Abstract: A turbine is provided with a turbine rotor blade, and a turbine housing having a scroll part extending along a circumferential direction of the turbine rotor blade. The scroll part is configured such that an A/R ratio of a flow passage area A to a distance R between an axis of the turbine rotor blade and a flow passage center of the scroll part has a concave distribution at least in a part of a graph where an abscissa represents a circumferential position around the axis of the turbine rotor blade and an ordinate represents the A/R ratio.