Patent attributes
A centrifugal compressor includes a housing, an impeller, an annular diffuser passage, and an annular movable member. The diffuser passage is defined in the housing by a shroud-side wall surface and a hub-side wall surface, which face each other. The movable member is configured to be projected from one of the shroud-side wall surface and the hub-side wall surface into the diffuser passage and to be retracted from the diffuser passage. The movable member has a through hole with a passage cross-sectional area smaller than that of the diffuser passage. The other of the shroud-side wall surface and the hub-side wall surface has an abutting portion against which the movable member abuts. When the movable member abuts against the abutting portion, the upstream side and the downstream side of the movable member in the diffuser passage communicate with each other via the through hole.
