Hydrodynamic bearing having inverted surface tension seals

Abstract

An improved hydrodynamic bearing comprising a longitudinally extending sleeve and an elongated shaft with the shaft being disposed within the sleeve for rotation relative thereto. A first thrust plate is coupled to one end of the shaft and a second thrust plate is coupled to the opposite end. A lubricant is disposed between the shaft and the sleeve as well as between the first and second thrust plates and the sleeve. The first thrust plate extends radially outward adjoining a corresponding first end of the sleeve forming a gap for containing the lubricant therebetween and the first thrust plate further extends axially inward toward a center of the bearing along an outer surface of the sleeve defining a surface tension seal forming gap therebetween. In a particular embodiment, the surface tension seal forming gap may be tapered to grow wider as it extends axially inward toward the center of the bearing to form a surface tension seal. The inverted surface tension seal configuration allows for an increased distance between the centers of force acting at the upper and lower bearing journals, thereby resulting in an enhanced tilt stiffness.

Dependencies are inferred from the claim text.