US Patent 9464669 Duplex bearing lubrication

A bearing system has first and second bearings each having an inner race. The inner races are mounted to a shaft. The first bearing inner race has a plurality of first ports. The second bearing inner race has a plurality of second ports. The shaft is insertable into the inner races in a plurality of orientations and has a plurality of outer diameter (OD) channels positioned to cooperate with at least the first bearing inner race to communicate with at least some of the first ports and at least some of the second ports. Regardless of said installed orientation, at least one of the second ports are in communication with at least one said inlet port along a flowpath bypassing all the first ports.