Patent ID: 7540664

Claim:
A fluid dynamic bearing, comprising: a first surface having at least a first groove pattern; and a second surface having at least a second groove pattern; wherein one of the surfaces is configured to be rotated relative to the other surface and the first and second groove patterns are located on their respective surfaces to cooperate in rotation to establish a pressure to support the relative rotation of the surfaces; wherein the first groove pattern and the second groove pattern are oppositely oriented in the context of relative rotation; wherein during rotation the first groove pattern creates a bearing pressure change at the first groove pattern, and the second groove pattern creates a bearing pressure change at the second groove pattern; wherein the first groove pattern comprises at least one set of first groove segments and the second groove pattern comprises at least one set of second groove segments; wherein each of the surfaces is a substantially flat surface, wherein the first segment extends radially from at or near an inner diameter of the first surface to at or near a portion of a radius of the first surface, and wherein the second segment extends radially from at or near a radial portion of the second surface corresponding to the radius of the first surface to at or near an outer diameter of the second surface.