which the amount of eccentricity with respect to the center of the shaft portion 9a increases in going from a lower portion to an upper portion the eccentric oil feeding passage 19 operates to draw oil in the bottom of the chamber 1 by centrifugal pumping action as the crank shaft 9 rotates and feeds same to the bearings 8 11 and 12 the mechanism for feeding oil to the bearings 8 11 and 12 will be described by referring to fig2 and 3 oil is fed to the plain bearing 8 of the orbiting scroll member 3 as follows the oil drawn from the bottom of the chamber 1 by the centrifugal pumping action of the eccentric oil feeding passage 19 flows into an oil chamber 20 defined between the upper end of the crank portion 9b of the crank shaft 9 and the orbiting scroll member 3 from which the oil flows through a recessed oil flow passage 21 formed on the outer peripheral surface of the crank portion 9b of the crank shaft 9 to lubricate the plain bearing 8 of the orbiting scroll member 3 and the crank portion 9b the oil that has lubricated the plain bearing 8 flows through an annular groove 23 formed in the junction of the crank portion 9b of the crank shaft 9 and a balance weight 22 to lubricate a thrust bearing 24 formed integrally with the plain bearing 8 in the lower portion thereof then the oil is released into an intermediate chamber 25 defined between.