Abstract: A variable nozzle unit is used in a turbine having a gas inflow passage which is sandwiched between a first flow passage wall surface and a second flow passage wall surface facing each other and through which a gas flowing from a scroll flow passage into a turbine impeller flows. The variable nozzle unit includes nozzle vanes, each of which is rotatably supported on both sides thereof by the first flow passage wall surface side and the second flow passage wall surface side and pivots about a pivotal axis parallel to the rotational axis of the turbine impeller in the gas inflow passage. An end face of the nozzle vane is formed with a cut face that is located closer to a leading edge than the pivotal axis, is cut out such that a gap between the cut face and the second flow passage wall surface is greater than other regions, and intersects the leading edge.

Abstract: A bottom surface of a housing recess of a turbine housing includes a close attachment portion in a continuous annular land shape, which is located radially outside a fitting recess. The close attachment portion is closely attached to a portion radially outside first support holes in a surface of a shroud ring opposite from its facing surface, by a fastening force of attachment bolts. The first support holes in the shroud ring communicate with an outlet side of a turbine impeller through a connection path and a cutout.

Abstract: A variable nozzle unit is used in a turbine having a gas inflow passage which is sandwiched between a first flow passage wall surface and a second flow passage wall surface facing each other and through which a gas flowing from a scroll flow passage into a turbine impeller flows. The variable nozzle unit includes nozzle vanes, each of which is rotatably supported on both sides thereof by the first flow passage wall surface side and the second flow passage wall surface side and pivots about a pivotal axis parallel to the rotational axis of the turbine impeller in the gas inflow passage. An end face of the nozzle vane is formed with a cut face that is located closer to a leading edge than the pivotal axis, is cut out such that a gap between the cut face and the second flow passage wall surface is greater than other regions, and intersects the leading edge.

Abstract: Three or more attachment pins are arranged on a right lateral surface of a nozzle ring at intervals. All the attachment pins are placed outside support holes in the nozzle ring in radial directions of the nozzle ring. A guide ring is provided across right lateral surfaces of the attachment pins. A first side guide member to support a right lateral surface of a drive ring in away that allows the right lateral surface to be in sliding contact therewith is provided to the right of the guide ring. A second side guide member to support a left lateral surface of the drive ring in a way that allows the left lateral surface to be in sliding contact therewith is provided to the left of the guide ring.

Abstract: A bottom surface of a housing recess of a turbine housing includes a close attachment portion in a continuous annular land shape, which is located radially outside a fitting recess. The close attachment portion is closely attached to a portion radially outside first support holes in a surface of a shroud ring opposite from its facing surface, by a fastening force of attachment bolts. The first support holes in the shroud ring communicate with an outlet side of a turbine impeller through a connection path and a cutout.

Abstract: Three or more attachment pins are arranged on a right lateral surface of a nozzle ring at intervals. All the attachment pins are placed outside support holes in the nozzle ring in radial directions of the nozzle ring. A guide ring is provided across right lateral surfaces of the attachment pins. A first side guide member to support a right lateral surface of a drive ring in away that allows the right lateral surface to be in sliding contact therewith is provided to the right of the guide ring. A second side guide member to support a left lateral surface of the drive ring in a way that allows the left lateral surface to be in sliding contact therewith is provided to the left of the guide ring.