Fluid dynamic bearing motor attached at both shaft ends

A fluid dynamic bearing motor comprising:

• a fixed shaft;
• a rotary member including a sleeve which is rotatably fitted on the shaft with a small gap therebetween;
• a first annular member fixedly provided to oppose a top end of the sleeve with a gap;
• a second annular member fixedly provided to oppose a bottom end and a lower periphery of the sleeve with a gap;
• a lubricant lying in the gaps between the sleeve and the shaft, and between the sleeve and the first annular member, and between the sleeve and the second annular member continuously, and having at least two interfaces with air near the upper region of the sleeve and on the lower portion of outer periphery of the sleeve;
• and
• a channel formed in the sleeve and having an intake portion near the portion of the sleeve adjacent to the outer region of the first annular member and an outlet portion near the periphery of the bottom end of the sleeve;
• and
• at least two groups of dynamic pressure generating grooves for supporting the rotary member in a floated condition due to pressure partially increased in the lubricant by the grooves, one of the groups being formed on either of the upper surface of the sleeve and the first annular member and the other being formed on either of the inner surface of the sleeve and a surface confronting thereto;
• and
• lubricant pressure adjuster for adjusting the outward lubricant pressure occurring in the channel around the outlet portion of the channel.