Disk drive device improved in anti-vibration characteristic

A disk drive device comprising:

• a base member;
• a rotating body;
• a bearing unit that is arranged on the base member and is configured to rotatably support the rotating body;
• and
• a drive unit configured to rotate the rotating body, and
• wherein the driving unit comprises:
• a magnet fixed to the rotating body;
• and
• a stator core fixed to the base member so as to be opposite to the magnet in a radial direction,
• wherein an attracting plate is fixed to the base member so as to be opposite to the magnet in an axial direction and to generate a magnetic attracting force between the magnet and the attracting plate,
• wherein the bearing unit includes:
• a lubricant holding portion in which lubricant is held between at least part of the base member and at least part of the rotating body;
• a first thrust dynamic pressure generating portion configured to generate a first dynamic pressure in a pump-in direction, in which the lubricant is led from an open end portion side of the lubricant holding portion toward an interior of the lubricant holding portion, the first dynamic pressure being generated in a part of the lubricant holding portion where a gap becomes narrower as the rotating body approaches the base member;
• and
• a second thrust dynamic pressure generating portion configured to generate a second dynamic pressure in a pump-out direction, which is opposite to the pump-in direction in which the first dynamic pressure is exerted, the pump-out direction being a direction in which the lubricant is guided from the interior of the lubricant holding portion toward the open end portion side of the lubricant holding portion, and the second dynamic pressure being generated in a part of the lubricant holding portion which is different from the part where the first thrust dynamic pressure generating portion is formed and in which a gap becomes narrower as the rotating body moves away from the base member, and
• the disk drive device further comprising:
• a radial dynamic pressure generating portion configured to support, in a part of the lubricant holding portion different from the parts where the first thrust dynamic pressure generating portion and the second thrust dynamic pressure generation portion are respectively formed, the rotating body in the radial direction with respect to the base member,
• wherein the first dynamic pressure generated by the first thrust dynamic pressure generating portion, the second dynamic pressure generated by the second thrust dynamic pressure generating portion, and a radial dynamic pressure generated by the radial dynamic pressure generating portion as combined is exerted in the pump-in direction as a whole, and
• wherein the first thrust dynamic pressure generating portion and the second thrust dynamic pressure generating portion have dynamic pressure generation characteristics in which, when the rotating body floating in the lubricant is biased in a rotational axis direction to a different position in which the rotating body remains floating, a sum of the changes, responsive to an axial movement of the rotating body and measured with reference to a state before the axial movement, in the second dynamic pressure in the pump-out direction is larger than that of the changes in the first dynamic pressure in the pump-in direction.