Abstract: For use with a machine including a wheel hub on a rotating shaft, moving-blade shafts secured to the hub and extended radially from the same, and fasteners on the moving-blade shafts, a bearing mounting for rotatably supporting each of the moving-blade shafts on the hub, characterized in that the wheel hub is formed with annular hollows of watertight design, each of which being open to an associated fastener on the hub facing the rotating shaft and accommodating a thrust roller bearing therein, and seals are located at the opening edges of each annular hollow in contact with the fastener.