High speed tool shaft bearing system

A bearing system for coupling a shaft of a tool to a power driven surgical instrument for rotation about an axis, said bearing system comprising:

• a support tube having an aperture extending longitudinally therethrough for receiving the shaft, and having a flange element extending inwardly into the aperture;
• a first bearing assembly within the aperture, and including a first bearing with an outer race abutting said flange element and with an inner race, a first interface cartridge engaging the inner race of the first bearing and having a first passage therethrough with spring elements extending radially into the first passage to engage the shaft, and a second bearing with an inner race abutting the first interface cartridge and with an outer race;
• a spring applying force against the outer race of the second bearing to bias said first bearing assembly axially within the aperture and against said flange element.