Patent ID: 8186980

Claim:
A scroll-type fluid machine comprising: a casing; a fixed scroll with a spiral lap portion vertically standing on a surface of an end plate, the fixed scroll being fixed to the casing; an orbiting scroll with a spiral lap portion vertically standing on a surface of an end plat, the orbiting scroll forming a plurality of fluid chambers between the fixed scroll and the orbiting scroll so as to compress or expand fluid in orbiting motion of the orbiting scroll; and an auxiliary crank device in which to prevent the orbiting scroll from being rotated, wherein: the auxiliary crank device comprises: a fixed-side bearing body provided on a casing side; an orbiting-side bearing body provided on an orbiting scroll side; and an auxiliary crank shaft in which a fixed-side shank is rotatably supported with the fixed-side bearing body, and an orbiting-side shank is rotatably supported with the orbiting-side bearing body; a tip portion of the fixed-side shank of the auxiliary crank shaft is fixed in a radius direction, and a tip portion of the orbiting-side shank of the auxiliary crank shaft is fixed in a radius direction; and between the tip portion of the fixed-side shank and the tip portion of the orbiting-side shank of the auxiliary crank shaft, a deformative portion, which has lower rigidity in a radius direction compared to the fixed-side shank and the orbiting-side shank, allowed to be deformed in a radius direction is provided.