Abstract: The combination with a housing or casing having an opening for projection outwardly therethrough of a shaft, the opening being of greater diameter than the shaft and rigidly receiving a mounting projecting beyond the casing and having a bore for journalling of the shaft, an inner bearing race fixedly engaged upon the mounting exteriorly of the casing for accommodating a plurality of discrete bearings, an outer race engaged to the shaft for rotation therewith, and a pulley or wheel member fixed on the outer race radially outwardly of the fixed inner race and mounting member.