Patent ID: 8315012

Claim:
A spindle motor for use in a disk drive apparatus, the spindle motor comprising: a stationary portion including a stator; and a rotating portion including a rotor magnet and arranged to be rotatably supported by the stationary portion; wherein the stationary portion includes: a base portion; and a shaft including a thrust plate and fixed to the base portion; the rotating portion includes: a sleeve portion including an axial end surface arranged opposite the thrust plate; and a first seal member arranged opposite the thrust plate on an opposite side of the thrust plate with respect to the sleeve portion; a radial gap defined between the shaft and the sleeve portion includes a radial bearing portion arranged to generate a fluid dynamic pressure defined therein; a first thrust gap defined between the thrust plate and the sleeve portion includes a first thrust bearing portion arranged to generate a fluid dynamic pressure defined therein; a second thrust gap defined between the thrust plate and the first seal member includes a second thrust bearing portion arranged to generate a fluid dynamic pressure defined therein; a first gap defined between the first seal member and the shaft includes a first capillary seal portion defined therein; a second gap defined between the shaft and the rotating portion on an opposite axial side of the sleeve portion with respect to the thrust plate includes a second capillary seal portion defined therein; the thrust plate includes a plate communicating hole arranged to connect the first and second thrust gaps with each other; the sleeve portion includes a sleeve communicating hole arranged to connect the first thrust gap with the opposite axial side of the sleeve portion with respect to the thrust plate; an end opening of the plate communicating hole and an end opening of the sleeve communicating hole are arranged either radially outward or radially inward of the first thrust bearing portion in the first thrust gap, while an opposite end opening of the plate communicating hole is arranged radially inward of the second thrust bearing portion in the second thrust gap; a lubricant is continuously arranged in a channel extending from the first capillary seal portion to the second capillary seal portion through the second thrust gap, a gap defined radially outside the thrust plate, the first thrust gap, and the radial gap; and the lubricant is arranged to fill a communicating channel extending from the first capillary seal portion to the second capillary seal portion through the plate communicating hole and the sleeve communicating hole.