US Patent 7306439 Orbiting scroll in a scroll fluid machine

A scroll fluid machine includes an orbiting scroll which has an orbiting end plate. The orbiting end plate has a plurality of extensions on the outer circumference. Each of the extensions has a boss in which a self-rotation-preventing eccentric shaft is pivotally supported. The extension has an easily-deformable portion to keep exact positional relationship between the extensions or to the center of the orbiting end plate of the extension.