A fluid dynamic pressure bearing apparatus includes a radial dynamic pressure
bearing
formed in a gap portion between a bearing member and a shaft member. The apparatus
also includes a thrust dynamic pressure bearing having a first thrust bearing portion
formed between a top surface of the thrust plate and a first facing member opposing
thereto in the axial direction and a second thrust bearing portion formed between
a bottom surface of the thrust plate and a second facing member opposing thereto
in an axial direction. Dynamic pressure generating grooves are formed on the radial
dynamic pressure bearing and the thrust dynamic pressure bearing. The shaft member
and the bearing member are rotated together as a rotation member, such that the
rotation member is supported in a position such that a gap space L1 of the
first thrust bearing portion is larger than a gap space L2 of the second
thrust bearing portion and the depth of the dynamic pressure generating grooves
where the gap space is smaller is formed shallower than that where the gap space
is larger.