Abstract: A protected, but unsealed rotor bearing for flowmeter turbine rotors and the like has an annular shoulder protruding axially from the rotor in concentric relation to the rotor axis in a manner that defines a cavity protruding axially into the rotor. An elongated bearing body with a cylindrical peripheral surface is mounted in a supporting frame and protrudes axially into the cavity. An axle on which the rotor is mounted protrudes into a bore in the bearing body such that the bearing interface is between the surface of the axle and the surface of the bore in the bearing body. A ball in the bore between the bearing body and the axle bears axial thrust. The peripheral surface of the bearing body does not contact the annular shoulder, but a face on the annular sholder that extends radially outward from adjacent the peripheral surface of the bearing body acts as a centrifugal flinger to dynamically divert contaminant particles away from the bearing surfaces.