Abstract: A screw compressor for compressing a working medium sucked through a suction opening and discharging the compressed working medium through a delivery opening, wherein the screw compressor includes: a male rotor and a female rotor that rotate while meshing with each other; a casing that houses the male rotor and the female rotor and is provided with a bore which forms a working chamber designed, together with the male rotor and the female rotor, to compress the working medium; a drive unit that rotationally drives at least one of the male rotor and the female rotor; a working chamber closing unit that forms a suction port for sucking the working medium into the working chamber and closes the working chamber when the working chamber reaches a specified capacity; and a suction space that connects the suction opening and the suction port to allow communication therebetween, wherein an open space that connects the suction opening and the suction port to allow communication therebetween is provided between a shaft

Abstract: A cup-shaped member in which the outer peripheral recesses are formed on the base end portion side of the outer peripheral surface of the cylinder portion, on which the bottom portion is disposed, by denting the outer peripheral surface radially inward of the cylinder portion at positions that correspond to the inner peripheral protrusions. The smooth outer peripheral portion is formed on the opening end side of the outer peripheral surface of the cylinder portion that is opposite to the side on which the bottom portion is disposed. The smooth outer peripheral portion has no corrugation and has generally the same diameter over the entire circumference of the outer peripheral surface, thereby increasing the strength of the cup-shaped member, and allowing the inner peripheral corrugated portion to be surely formed.