A compressor is disclosed having a gas extraction passage, internally formed
in
a drive shaft and continuously communicating with a crank chamber and a suction
chamber, that has an inlet portion, to be exposed to the crank chamber, is formed
in the drive shaft in a radial direction. As a result, mist-like oil accompanied
by blow-by gas tending to flow into the gas extraction passage initially impinges
upon and adheres to an inner peripheral surface of the inlet portion of the gas
extraction passage due to rotational movement of the drive shaft. Namely, oil separation
(gas-liquid separation) occurs at the inlet portion of the gas extraction passage.
Then, oil separated from the blow-by gas at the inlet portion of the gas extraction
passage is forcibly returned to the crank chamber due to a centrifugal force caused
by rotational movement of the drive shaft. Accordingly, the compressor has a structure
in which oil accompanied by blow-by gas is hard to escape the suction chamber.