Abstract: The support structure for a rotatable shaft of a turbomachine includes tilt pad bearings mounted within an outboard seal ring so that the tilt pad bearings urge the outboard seal ring to be concentric with the shaft. A squeeze film damper acts between the outboard seal ring and the wall of a housing cavity in which the outboard seal ring is mounted, to center the outboard seal ring within the housing cavity. The squeeze film damper chamber is defined by two O-rings positioned in two annular grooves eccentrically formed in the outboard seal ring. A high pressure lubricant is delivered to a high pressure chamber to which the smaller inboard end surface of the outboard seal ring is exposed, while a lower pressure lubricant is delivered to an intermediate pressure chamber to which the larger outboard end surface of the outboard seal ring is exposed, for pressure-balancing the outboard seal ring axially.