Systems and methods for rotor bearings that enable improved oil circulation, wherein axial grooves are formed in the outer periphery of each bearing to form channels that allow axial flow of oil through the channels. Each bearing includes a collar, a sleeve and an interference ring. The collar has a bore through its center in which a rotatable sleeve is positioned. The outer periphery of the collar has a circumferential groove and at least one axial groove that extends from one face of the collar to the other. An axially permeable interference ring positioned within the circumferential groove extends radially outward from the groove beyond the outer periphery of the collar. The interference ring (e.g., a looped coil spring) allows fluid in the axial groove to flow through the interference ring. The axial groove may have a different depth than the circumferential groove.