Dynamic pressure bearing and spindle motor using the same

摘要

A dynamic pressure bearing has a reduced axial dimension and is constructed to ensure smooth feeding of a lubricating oil. The dynamic pressure bearing includes a communicating hole and at least one tapered seal, and is constructed such that an opening angle of one of the at least one tapered seal through which oil feeding is possible is in a range of about 30 degrees inclusive to about 180 degrees exclusive, a tapered seal wall surface depth W1 of the tapered seal is about 0.3 mm or more, and a sum of distances over which the lubricating oil travels from both sides of an end portion of the communicating hole in a cross-section beyond a wall surface of the communicating hole along a wall surface opposite the end portion of the communicating hole exceeds an inside diameter of the communicating hole.