Bearing mechanism, spindle motor including the bearing mechanism and electronic equipment including the spindle motor

摘要

A bearing mechanism includes a stationary portion and a rotating portion. The stationary portion includes a shaft portion and a plate portion. The rotating portion includes a sleeve including an annular portion, a cylindrical portion, an annular bottom surface, and a first communication hole. The rotating portion includes a ring member arranged to cover at least a portion of an opening of the first communication hole, and faces the plate portion via a first gap. A pumping groove array is disposed in the plate portion or the ring member. A second communication hole is disposed between the ring member and the annular bottom surface, and connected to the first communication hole. At least a portion of the opening of the second communication hole is positioned on a farther radial direction inner side than the pumping groove array.