Abstract: A bearing fits over the journal of a rail car axle and within an adaptor that is received within a pedestal opening of the side frame of a rail car truck. The bearing includes an outer race in the form of a double cup, an inner race in the form of two cones, and rolling elements in the form of tapered rollers. The cup and cones have raceways, and the tapered rollers are arranged in two rows between the raceways. Seals close the ends of the bearing, establishing dynamic fluid barriers around wear rings that encircle the journal beyond both ends of the bearing. The bearing between its two rows of tapered rollers contains a generator for producing electrical energy.