Patent ID: 8395861

Claim:
A disk drive device, comprising a base member; a bearing unit that is disposed in the base member and that rotatably supports a recording disk with respect to the base member; and a drive unit configured to rotationally drive the recording disk supported by the bearing unit, the bearing unit including: a shaft that is a center of rotation; a sleeve that has an accommodating portion in which the shaft is accommodated and that is configured to permit relative rotation around the shaft; a radial space defined by an inner wall surface of the accommodating portion of the sleeve and an outer wall surface of the shaft; a radial dynamic pressure groove configured to generate a radial dynamic pressure and formed in at least one of the inner wall surface of the sleeve and the outer wall surface of the shaft that define the radial space; a lubricant charged into the radial space; and a porous member that is disposed in at least a portion of a charging space into which the lubricant is charged, for capturing foreign matter contained in the lubricant; wherein the porous member is a filter of a multi-layer structure, and a density of the filter is varied from a rough state to a dense state in correspondence with a moving direction of foreign matter contained in the lubricant.