SCREW COMPRESSOR AND REFRIGERATION CYCLE DEVICE

A screw compressor according to an embodiment of the present invention includes an electric motor an rotation speed of which can be changed, a screw rotor including a plurality of screw grooves on an outer circumferential surface, a screw shaft to transmit a driving force of the electric motor to the screw rotor and rotate the screw rotor, a first gate rotor and a second gate rotor respectively disposed on both sides of the screw rotor point-symmetrically with respect to the screw shaft and including, in outer circumferential portions, a plurality of teeth meshed with the screw grooves, a casing having a cylindrical shape to house the screw rotor inside a cylinder, a bypass device to cause a first compression chamber, which is a space surrounded by the first gate rotor, the screw groove, and the casing, and a low-pressure chamber having a suction pressure atmosphere to communicate, and an economizer port provided in the casing to cause fluid flowing from an outside to flow into the first compression chamber.