A centrifugal compressor includes: a housing including an intake flow path; a compressor impeller arranged in the intake flow path and including a plurality of blades; an accommodation chamber formed upstream of the blades in a flow of intake air in the housing; a movable member arranged in the accommodation chamber and movable to a protruding position where the movable member protrudes into the intake flow path and to a retracted position where the movable member is retracted from the intake flow path; a plurality of slits formed closer to the blades with respect to the accommodation chamber in the housing and connected to the intake flow path; a plurality of compartment walls circumferentially separating the plurality of slits; and an outer circumferential wall connecting radially outer ends of the plurality of compartment walls.

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. The valve body has a first surface at the end on the upstream side, which faces the first wall surface, gradually approaches the first wall surface from the upstream side to the downstream side and thereafter gradually goes away therefrom, and a second surface which faces the second wall surface.

A centrifugal compressor for a turbocharger includes an inlet-adjustment mechanism in an air inlet for the compressor, operable to move between an open position and a closed position in the air inlet. The inlet-adjustment mechanism includes a variable-geometry orifice actuated by a rotatable actuator ring. In the closed position, the orifice's inner diameter is smaller than that of a shroud surface of the compressor housing and therefore dictates the effective inlet diameter for the compressor. In the open position the orifice no longer forms an inner diameter smaller than the shroud surface, so that the effective inlet diameter is determined by the shroud surface.

An assembly for a two-stage turbocharger can include a first turbocharger stage and a second turbocharger stage where one of the stages includes a boss that includes a bore; an exhaust bypass valve that includes an arm pivotable to orient the exhaust bypass valve in an open state and a closed state; a valve shaft disposed at least in part in the bore and operatively coupled to the exhaust bypass valve where the valve shaft includes an inner end, an outer end and an axial stop disposed between the inner end and the outer end; an outer bushing disposed at least in part in the bore and located axially along the valve shaft; and an inner bushing disposed at least in part in the bore and located axially along the valve shaft between the axial stop and a portion of the arm of the exhaust bypass valve.

An inlet guide vane assembly is disclosed, which comprises: a housing, configured with a first penetration part and a plurality of first grooves; at least one fixing ring, each configured with a second penetration part and a plurality of second grooves; at least one rotary ring, each configured with a third penetration part and a plurality of sliding chutes, wherein the first, the second and the third penetration parts are arranged in communication with one another; a plurality of vane units, each vane unit is composed of a vane, a linkage and a sliding block; and at least one driving unit, for driving one vane of the plural vanes to swing, thus driving the rotary ring to rotate simultaneously, bringing along the other vanes to swing, enabling the sliding blocks to slide inside corresponding sliding chutes, and consequently flipping the vane from a first state to a second state.