the center of gravity of the rotor of a rolling rotor motor and the center of gravity of the orbiting scroll of a scroll compressor are located on diametrically opposite sides of the centerline of the stator . the rotor and orbiting scroll are connected through a plurality of circumferentially spaced links which are pivotable about fixed axes whereby movement of the rotor produces movement of the orbiting scroll while the orbiting scroll serves as a counterweight with respect to the rotor .