Patent ID: 8308420

Claim:
A centrifugal compressor comprising a rotary shaft, a circular plate supported by the rotary shaft, and a plurality of blades substantially radially disposed and protruding from the circular plate, and having flow channels of a cross sectional area formed between the blades, in order to suck fluid from a front area in a shaft direction by rotating the circular plate with the rotary shaft and then discharge the fluid, which increases in pressure while passing through the flow channels, in a centrifugal direction, wherein, assuming that a blade angle of a shroud side of the blade is a first angle and a blade angle of a hub side disposed at the circular plate is a second angle, the shroud side is formed in a curved shape having a first angle distribution from the front area in the shaft direction toward the centrifugal direction in which the first angle distribution has a local maximum point at which the cross sectional area of the flow channel changes from expansion to reduction that is before a substantially middle portion and has a local minimum point after the substantially middle portion at which the cross sectional area of the flow channel changes from reduction to expansion, and the hub side is formed in a curved shape having a second angle distribution from the front area in the shaft direction toward the centrifugal direction in which the second angle distribution has a local maximum point at which the cross sectional area of the flow channel changes from expansion to reduction before the substantially middle portion.