Patent ID: 8863513

Claim:
A centrifugal compressor comprising: a housing assembly that includes a first housing which supports a rotating shaft so as to be rotatable about an axis, the rotating shaft having an impeller on an end portion of itself, and a second housing which houses the impeller inside and is assembled with the first housing so as to be aligned in the direction of the axis with the first housing, wherein a diffuser serving as a passage space communicated with an exit side of the impeller is formed by a first diffuser wall portion of a first housing side and a second diffuser wall portion of a second housing side on outer periphery of the impeller, and a movable vane that includes a base portion which is arranged in a storage chamber provided in the first diffuser wall portion and has a facing surface opposing to the second diffuser wall portion, and vane portions which project from the facing surface to a second diffuser wall portion side, wherein the movable vane is movable in the direction of the axis between a projected position where the facing surface contacts with a positioning surface provided in the storage chamber and the vane portions project in the diffuser and a retracted position where the vane portions are retracted to a first diffuser wall portion side further than the projected position, wherein the first housing is provided with a mounting surface located in a direction perpendicular to the direction of the axis, the second housing includes an affixing portion projecting to the first housing side further than the second diffuser wall portion, and a fastening surface being provided to the affixing portion and located in a direction perpendicular to the direction of the axis, wherein the second housing is assembled with the first housing by attaching the fastening surface to the mounting surface, and the positioning surface is provided in the storage chamber so as to be flush with the fastening surface, wherein the first diffuser wall portion is provided with a concave portion having a concavity extending in the direction of the axis further than the mounting surface, the concave portion housing the base portion such that the base portion is movable in the direction of the axis, the concave portion comprising the storage chamber, the fastening surface is attached to the mounting surface and a part of the fastening surface covers a part of the concave portion, wherein a diffuser plate is provided so as to cover a remaining part of the concave portion, and the diffuser plate is provided with a support member extending in the direction of the axis from a first housing side surface of the diffuser plate so that a distance between the first housing side surface and the second housing side is less than a distance between the fastening surface and the second housing side.