ROTARY COMPRESSOR

PROBLEM TO BE SOLVED: To prevent a moment from acting on a piston and to prevent sliding loss by making approximately the center of the effective length of a bearing part constituted of a contact part between the internal circumferential face of the piston and the outer circumference of an eccentric shaft of a drive shaft coincide with the center of the cylinder length. SOLUTION: When a piston 6 revolves along the inner wall of a cylinder chamber 4a in such a state as swinging with the rotation center position of a guide set to a fulcrum via a blade by the rotation of a drive shaft 5, a refrigerant gas sucked from a suction port is compressed and discharged from a discharge port. In this case, relieves 5f of equal length (a) are formed in top/bottom both end faces 5b, 5c of an eccentric shaft 5a of the drive shaft 5. Where the cylinder height is set to H, the effective length Lb of a bearing part constituted of a contact part between the internal circumferential face 6g of the piston 6 and the outer circumferential face of an eccentric shaft 5a of the drive shaft 5 is formulated Lb=H-2a and the central position of the effective length Lb of the bearing part is set to (1/2)H.