Spindle motor having air dynamic pressure bearing and rotating device having the spindle motor as driving source

In a spindle motor comprised of a rotor having a rotor magnet and a stator having a stator coil:

• an air dynamic pressure bearing for supporting the rotor for rotation about a rotational axis relative to the stator, the air dynamic pressure bearing comprising a conical dynamic pressure bearing portion comprised of a convex side bearing member having a conical convex portion and a column portion, a bore disposed in the convex side bearing member and extending along the rotational axis, a concave side bearing member having a conical concave portion receiving the conical convex portion, and dynamic pressure generating grooves formed on one of a surface of the conical convex portion and a surface of the conical concave portion;
• a radial dynamic pressure bearing portion comprised of a shaft extending through the bore of the dynamic pressure bearing portion and having a first end integrally connected to the concave side bearing member, and dynamic pressure grooves formed on one of an outer circumferential surface of the shaft and an inner circumferential surface of the bore;
• and a thrust dynamic pressure bearing portion comprised of a generally disk-shaped bearing member fixed at a second end of the shaft and having a surface disposed in confronting relation to an end surface of the column portion of the convex side bearing member, and dynamic pressure grooves formed at one of the surface of the disk-shaped bearing member and the end surface of the column portion of the convex side bearing member.