VARIABLE DIFFUSER AND COMPRESSOR

摘要

A variable diffuser for a compressor, having further increased efficiency. In the variable diffuser (30), a diffuser passage (33) for recovering static pressure from dynamic pressure by reducing the speed of an air current discharged from the outer peripheral end of an impeller rotating in a housing is formed between a hub-side wall surface (32a) and a shroud-side wall surface (31a), and diffuser vanes are installed in the diffuser passage (33). Fixed vanes (35) and movable vanes (34) serving as the diffuser vanes are alternately circumferentially fixed to a fixed disk (32) and a movable disk (31) that form the hub-side wall surface (32a) and the shroud-side wall surface (31a). The variable diffuser also has a drive device (40) for rotating the movable disk (31) coaxially with the impeller.