Abstract: A wastegate valve device according to at least one embodiment is a wastegate valve device disposed on a bypass passage bypassing a turbine of a turbocharger arranged on an exhaust gas passage of an engine, including: a valve seat surface formed at an outlet of the bypass passage; and a wastegate valve body which includes a support arm supported rotatably about an axis and a valve body supported by the support arm, the valve body being configured to come into and out of contact with the valve seat surface in accordance with rotation of the support arm. In the wastegate valve device according to at least one embodiment, the valve seat surface is inclined with respect to a direction orthogonal to an axial direction of the bypass passage, as viewed from a direction of the above-described axis.

Abstract: This turbocharger includes: an impeller which includes a hub provided to be rotatable around a center axis and a plurality of turbine blades arranged on the outside of the hub in a radial direction at intervals in a circumferential direction around the center axis; and a turbine housing which is disposed on the outside of the impeller in the radial direction and forms a scroll flow path guiding an exhaust gas toward the impeller on the inside of the radial direction while turning the exhaust gas in the circumferential direction, wherein a flow path width in the circumferential direction of at least one of a plurality of inter-blade flow path portions formed between the plurality of turbine blades is different from a flow path width of the another of the plurality of inter-blade flow path portions.

Abstract: A scroll passage of a turbine housing includes: an outer peripheral surface extending along an axial direction of the turbine housing; an inner peripheral surface disposed inward of the outer peripheral surface; a one-side surface extending along the radial direction; an other-side surface disposed closer to an outlet of the housing; a one-side outer peripheral R portion connecting the one-side surface and the outer peripheral surface; an other-side outer peripheral R portion connecting the other-side surface and the outer peripheral surface; and an other-side inner peripheral R portion connecting the other-side surface and the inner peripheral surface. A ratio of a width dimension of the scroll passage to an R dimension of each portion is defined as a peripheral R ratio, and the peripheral R ratio has an R ratio increasing region the ratio increases from upstream to downstream in the scroll passage.

Abstract: A turbine wheel according to at least one embodiment is a turbine wheel connected to a rotational shaft and configured to rotate about an axis and includes: a hub having a hub surface oblique to the axis in a cross-section along the axis; and a plurality of blades disposed on the hub surface. The turbine wheel includes a plurality of passages each of which is formed between two adjacent blades of the plurality of blades, and a relationship of Aen/Aave>1.01 is satisfied, where Aen is an area of a throat portion of a throat enlarged passage which is at least one of the plurality of passages, and Aave is an average area of throat portions of the plurality of passages.

Abstract: A wastegate valve device according to at least one embodiment is a wastegate valve device disposed on a bypass passage bypassing a turbine of a turbocharger arranged on an exhaust gas passage of an engine, including: a valve seat surface formed at an outlet of the bypass passage; and a wastegate valve body which includes a support arm supported rotatably about an axis and a valve body supported by the support arm, the valve body being configured to come into and out of contact with the valve seat surface in accordance with rotation of the support arm. In the wastegate valve device according to at least one embodiment, the valve seat surface is inclined with respect to a direction orthogonal to an axial direction of the bypass passage, as viewed from a direction of the above-described axis.

Abstract: This turbocharger includes: an impeller which includes a hub provided to be rotatable around a center axis and a plurality of turbine blades arranged on the outside of the hub in a radial direction at intervals in a circumferential direction around the center axis; and a turbine housing which is disposed on the outside of the impeller in the radial direction and forms a scroll flow path guiding an exhaust gas toward the impeller on the inside of the radial direction while turning the exhaust gas in the circumferential direction, wherein a flow path width in the circumferential direction of at least one of a plurality of inter-blade flow path portions formed between the plurality of turbine blades is different from a flow path width of the another of the plurality of inter-blade flow path portions.

Abstract: A turbine housing has a scroll passage.

Abstract: A turbine rotor blade according to at least one embodiment of the present invention is to be connected to a rotational shaft so as to be rotatable around an axis and includes: a hub having a hub surface inclined with respect to the axis in a cross-section along the axis; at least one rotor blade disposed on the hub surface; and a connection passage disposed inside the turbine rotor blade and connecting a first opening disposed in the at least one rotor blade and a second opening disposed downstream of the first opening in the turbine rotor blade.

Abstract: A turbine blade configured to be coupled to a rotational shaft and rotated around an axis includes: a hub having a hub surface which is inclined with respect to the axis in a cross section along the axis; a rotor blade disposed on the hub surface; and at least one rib formed on a blade surface of the rotor blade, the at least one rib extending in a direction which intersects with a span direction of the rotor blade in a meridional plane of the rotor blade.

Abstract: A turbine rotor blade according to at least one embodiment to be connected to a rotational shaft so as to be rotatable around an axis includes a hub having a hub surface inclined with respect to the axis in a cross-section along the axis; and a plurality of rotor blades disposed on the hub surface. In a throat portion where a blade-to-blade distance between two adjacent rotor blades is smallest, a value (Lt/r) obtained by dividing the blade-to-blade Lt at a given radial position by a distance r from the axis to the radial position is maximum at a position where a dimensionless span length is in a range of 0.2 to 0.65, assuming that the dimensionless span length is 0 at a position of a root end portion on a hub side and is 1 at a position of a tip end portion opposite to the hub side.

Abstract: A turbine wheel (12) is provided with: a disc (22) provided so as to be capable of rotating about a center axis (C); and a plurality of blades (23) provided to a disc surface (22f) at intervals in a circumferential direction, the blades (23) causing a gas guided in from radially outward leading edges (23f) to be expelled from trailing edges (23r) disposed on one side of each of the blades along the direction of the center axis (C). In each of the blades (23), in an area on one side along the direction of the center axis (C) including the trailing edge (23r), there is provided a concave surface (27) in which a positive-pressure surface (23p) on the rear side in a rotational direction (R) is recessed forward in the rotational direction (R), causing the gas to be dispersed entirely in the radial direction of the blade (23).

Abstract: A fixed vane turbocharger includes: an impeller; a housing including, inside thereof, an impeller housing space which accommodates the impeller, a scroll flow passage formed on a radially outer side of the impeller, and a communication flow passage which brings the impeller housing space and the scroll flow passage into communication; and at least one fixed vane unit disposed in the communication flow passage and fixed to a portion of the housing on an inner side of the scroll flow passage with respect to a radial direction of the impeller. Each of the at least one fixed vane unit includes at least two vane portions and a coupling portion coupling the two vane portions, and is formed of a single sheet metal member.

Abstract: A diffuser includes a connection section and a body section. The connection section extends from an outlet of turbine rotor blades. The body section is connected to an end of the connection section on a downstream side and has a larger flow passage sectional area than the connection section. The shape of the flow passage sectional surface of the connection section is formed into a circle at an outlet of the turbine rotor blades and is formed into an ellipse at an inlet of the body section. The shape of the flow passage sectional surface of the connection section is further formed to be gradually enlarged in a long-axis direction of the ellipse from the outlet of the turbine rotor blades toward the inlet of the body section.

Abstract: A turbine for a turbocharger includes: a turbine impeller coupled to a compressor impeller via a rotational shaft; a turbine casing disposed so as to cover the turbine impeller, the turbine casing including a scroll flow passage and a scroll outlet portion disposed on an inner side, in a radial direction, of the scroll flow passage, for guiding exhaust gas from the scroll flow passage to the turbine impeller; and a back-surface side member disposed so as to face a back surface of the turbine impeller. The back-surface side member includes a protruding portion disposed on an impeller facing surface which faces the back surface of the turbine impeller, the protruding portion protruding toward the back surface and extending in a circumferential direction.

Abstract: A variable geometry turbocharger includes: a turbine rotor; and a variable nozzle mechanism for adjusting a flow of exhaust gas to the turbine rotor from a scroll flow passage formed on a radially outer side of the turbine rotor. The variable nozzle mechanism includes: a nozzle vane disposed in an exhaust gas flow passage for guiding the exhaust gas to the turbine rotor from the scroll flow passage; a support wall forming a flow passage wall on a first side of the exhaust gas flow passage with respect to an axial direction of the turbine rotor and supporting the nozzle vane rotatably in a cantilever fashion; and a non-support wall forming a flow passage wall on a second side of the exhaust gas flow passage with respect to the axial direction. Of an end surface of the nozzle vane on a side of the non-support wall, an edge portion on a side of a pressure surface includes a non-support-wall side linear portion formed to have a linear shape.

Abstract: A turbine rotor blade according to at least one embodiment to be connected to a rotational shaft so as to be rotatable around an axis includes a hub having a hub surface inclined with respect to the axis in a cross-section along the axis; and a plurality of rotor blades disposed on the hub surface. In a throat portion where a blade-to-blade distance between two adjacent rotor blades is smallest, a value (Lt/r) obtained by dividing the blade-to-blade Lt at a given radial position by a distance r from the axis to the radial position is maximum at a position where a dimensionless span length is in a range of 0.2 to 0.65, assuming that the dimensionless span length is 0 at a position of a root end portion on a hub side and is 1 at a position of a tip end portion opposite to the hub side.

Abstract: A turbine rotor blade according to at least one embodiment of the present invention is to be connected to a rotational shaft so as to be rotatable around an axis and includes: a hub having a hub surface inclined with respect to the axis in a cross-section along the axis; at least one rotor blade disposed on the hub surface; and a connection passage disposed inside the turbine rotor blade and connecting a first opening disposed in the at least one rotor blade and a second opening disposed downstream of the first opening in the turbine rotor blade.

Abstract: A turbine housing includes: a housing body which is configured to accommodate a turbine wheel and which includes an inlet section forming an inlet flow passage for guiding exhaust gas to the turbine wheel, and an outlet section forming an outlet flow passage for discharging the exhaust gas from the turbine wheel; and at least one sleeve disposed along an inner wall surface of at least one of the inlet section or the outlet section of the housing body. The at least one sleeve includes a plurality of sections divided along a flow direction of the exhaust gas.

Abstract: A turbine housing includes: a housing body which includes a turbine housing part housing a turbine wheel, an inlet section forming an inlet flow passage for guiding exhaust gas to the turbine housing part, an outlet section forming an outlet flow passage for discharging the exhaust gas from the turbine housing part, and a waste-gate flow passage which brings the inlet flow passage and the outlet flow passage into communication so as to bypass the turbine housing part; and a sleeve disposed along an inner wall surface of the housing body forming the waste gate flow passage, at least on a downstream side of the waste-gate flow passage of the housing body with respect to a flow direction of the exhaust gas.

Abstract: A diffuser includes a connection section and a body section. The connection section extends from an outlet of turbine rotor blades. The body section is connected to an end of the connection section on a downstream side and has a larger flow passage sectional area than the connection section. The shape of the flow passage sectional surface of the connection section is formed into a circle at an outlet of the turbine rotor blades and is formed into an ellipse at an inlet of the body section. The shape of the flow passage sectional surface of the connection section is further formed to be gradually enlarged in a long-axis direction of the ellipse from the outlet of the turbine rotor blades toward the inlet of the body section.