Abstract: A variable geometry turbine includes: a turbine rotor; a scroll passage forming part which forms a scroll passage; an exhaust gas passage forming part which forms an exhaust gas passage for introducing an exhaust gas from the scroll passage to the turbine rotor; and a variable nozzle unit including a plurality of nozzle vanes disposed in the exhaust gas passage and configured to be rotatable about respective rotation centers. The exhaust gas passage forming part includes: a first plate member having an annular first plate part; and a second plate member having an annular second plate part which defines the exhaust gas passage between the first plate part and the second plate part and is disposed closer to a turbine outlet than the first plate part in an axial direction of the turbine rotor.

Abstract: A sealing structure of a turbocharger includes a turbine housing including a scroll channel, a nozzle mount, a nozzle plate defining, with the nozzle mount, an exhaust gas channel for introducing an exhaust gas from the scroll channel to a turbine wheel, the nozzle plate including an annular plate portion that has a channel wall surface defining the exhaust gas channel and a tubular portion that extends from an inner peripheral end portion on a back surface of the annular plate portion toward a first inner wall surface of the turbine housing, and a sealing device for sealing a section between the first inner wall surface and an end surface of the tubular portion.

Abstract: A variable nozzle device includes: a nozzle mount; a plurality of nozzle vanes; a drive ring being having a plurality of receiving portions disposed at different positions along a circumferential direction; and a plurality of lever plates each having a fixed portion to be fixed to corresponding one of the plurality of nozzle vanes and an engaging portion to be engaged with corresponding one of the plurality of receiving portions of the drive ring. The receiving portions include a first-side guide surface and a second-side guide surface. The engaging portions each include a first-side roll surface which is to be in contact with the first-side guide surface and a second-side roll surface which is to be in contact with the second-side guide surface. The first-side roll surface includes a lever-plate-side linear portion extending linearly in at least a part of a range which is to be in contact with the first-side guide surface.

Abstract: A variable nozzle device includes: a nozzle mount; a plurality of nozzle vanes; a drive ring being having a plurality of receiving portions disposed at different positions along a circumferential direction; and a plurality of lever plates each having a fixed portion to be fixed to corresponding one of the plurality of nozzle vanes and an engaging portion to be engaged with corresponding one of the plurality of receiving portions of the drive ring. The receiving portions include a first-side guide surface and a second-side guide surface. The engaging portions each include a first-side roll surface which is to be in contact with the first-side guide surface and a second-side roll surface which is to be in contact with the second-side guide surface. The first-side roll surface includes a lever-plate-side linear portion extending linearly in at least a part of a range which is to be in contact with the first-side guide surface.

Abstract: A sealing structure of a turbocharger includes a turbine housing including a scroll channel, a nozzle mount, a nozzle plate defining, with the nozzle mount, an exhaust gas channel for introducing an exhaust gas from the scroll channel to a turbine wheel, the nozzle plate including an annular plate portion that has a channel wall surface defining the exhaust gas channel and a tubular portion that extends from an inner peripheral end portion on a back surface of the annular plate portion toward a first inner wall surface of the turbine housing, and a sealing device for sealing a section between the first inner wall surface and an end surface of the tubular portion.

Abstract: A variable nozzle mechanism includes: a nozzle mount having an annular shape; a plurality of nozzle vanes supported rotatably at a plurality of respective locations along a circumferential direction of the nozzle mount; and a drive ring disposed rotatably with respect to the nozzle mount, the drive ring being configured to transmit a driving force to the nozzle vanes so that a vane angle of the nozzle vanes is variable and to rotate the nozzle vanes. The drive ring includes: a low-rigidity region; and a high-rigidity region including an uneven portion in a thickness direction of the drive ring, and having a greater cross-sectional secondary moment than the low-rigidity region in a cross section along a radial direction of the drive ring. The low-rigidity region and the high-rigidity region are disposed alternately in the circumferential direction.

Abstract: A turbocharger includes: a turbine wheel; a turbine housing; a bearing housing; a shroud having a facing surface which faces a tip of a blade of the turbine wheel and being configured to surround the turbine wheel, the shroud comprising a separate member from the turbine housing and being disposed inside the turbine housing via a gap with respect to the turbine housing; a mount supported to at least one of the turbine housing or the bearing housing, at a position closer to the bearing housing than a scroll flow path in an axial direction of the turbine wheel; and at least one connection part connecting the mount and the shroud.

Abstract: An expansion turbine including a turbine housing, a plurality of variable nozzles inside the turbine housing at intervals in a circumferential direction of the expansion turbine, the variable nozzles being configured to be rotatable about a rotation shaft, and a turbine wheel 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 which faces tips of the turbine blades, and a second wall surface which faces the first wall surface across a flow path 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 variable nozzle mechanism includes: a nozzle mount having an annular shape; a plurality of nozzle vanes supported rotatably at a plurality of respective locations along a circumferential direction of the nozzle mount; and a drive ring disposed rotatably with respect to the nozzle mount, the drive ring being configured to transmit a driving force to the nozzle vanes so that a vane angle of the nozzle vanes is variable and to rotate the nozzle vanes. The drive ring includes: a low-rigidity region; and a high-rigidity region including an uneven portion in a thickness direction of the drive ring, and having a greater cross-sectional secondary moment than the low-rigidity region in a cross section along a radial direction of the drive ring. The low-rigidity region and the high-rigidity region are disposed alternately in the circumferential direction.

Abstract: A turbocharger includes: a turbine wheel; a turbine housing; a bearing housing; a shroud having a facing surface which faces a tip of a blade of the turbine wheel and being configured to surround the turbine wheel, the shroud comprising a separate member from the turbine housing and being disposed inside the turbine housing via a gap with respect to the turbine housing; a mount supported to at least one of the turbine housing or the bearing housing, at a position closer to the bearing housing than a scroll flow path in an axial direction of the turbine wheel; and at least one connection part connecting the mount and the shroud.

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.