Patent ID: 8708677

Claim:
A screw compressor, comprising: a screw rotor provided with multiple helical grooves; and a gate rotor provided with multiple gates meshing with the helical grooves to form at least one a compression chamber between at least one of the helical grooves and at least one of the gates, with the compression chamber being configured and arranged such that refrigerant taken-in from a starting-end side of the helical groove is compressed and discharged from a dead-end side of the helical groove; and an injection mechanism configured and arranged to inject oil or refrigerant from a discharge hole thereof into the compression chamber, the injection mechanism being further configured and arranged to inject oil or refrigerant to only a bottom wall surface and one sidewall surface of sidewall surfaces of the helical groove, with the one sidewall surface being formed on a forward side of an advance direction of the gate meshing with the helical groove.