US Patent 11177489 Centrifugal compressor with diffuser

A centrifugal compressor includes a rotation shaft, a compressor impeller attached to one end of the rotation shaft, and a first wall surface and a second wall surface formed inside a housing so as to face each other in an axial direction. A diffuser is formed between the first wall surface and the second wall surface in the axial direction, and a wall portion separates the diffuser from an axial space inside the housing in which the rotation shaft extends. The wall portion includes at least one extraction hole that fluidly couples the diffuser to the axial spate and that is configured to extract a gas from the diffuser.