SPINDLE MOTOR, ELECTRONICS DEVICE AND DISK DRIVE APPARATUS

摘要

A rotating portion of a spindle motor includes a rotor magnet, a circular plate portion, and an annular raised portion that projects downward from the circular plate portion. A stationary portion includes a stator, a base portion, and an annular recessed portion configured to accommodate the raised portion. The raised portion includes an inner circumferential surface and an outer circumferential surface. The inner circumferential surface is positioned radially opposite a first side surface of the recessed portion with a first minute gap intervening therebetween. The outer circumferential surface is positioned radially opposite a second side surface of the recessed portion with a second minute gap intervening therebetween. The first minute gap has an axial dimension greater than an axial dimension of a seal portion.

主权项

1. A spindle motor comprising:
a stationary portion; a rotating portion configured to rotate about a central axis with respect to the stationary portion; and a bearing configured to support the rotating portion; wherein the bearing includes:
a stationary bearing portion fixed to the stationary portion;a rotatable bearing portion configured to rotate together with the rotating portion;a seal portion located between a wall surface of the rotatable bearing portion and a wall surface of the stationary bearing portion;a lubricating fluid positioned to intervene between the rotatable bearing portion and the stationary bearing portion; anda liquid surface of the lubricating fluid located in the seal portion; the rotating portion includes:
a rotor magnet;a circular or substantially circular plate portion configured to extend around the central axis; andan annular or substantially annular raised portion configured to project downward from the circular or substantially circular plate portion; the stationary portion includes:
a stator arranged opposite to the rotor magnet with a gap intervening therebetween;a base portion configured to extend around the central axis, and configured to have the stator fixed thereto; andan annular or substantially annular recessed portion configured to accommodate the raised portion, and including a first side surface and a second side surface; the raised portion includes:
an inner circumferential surface positioned radially opposite the first side surface of the recessed portion with a first minute gap intervening therebetween; andan outer circumferential surface positioned radially opposite the second side surface of the recessed portion with a second minute gap intervening therebetween; and the first minute gap is configured to have an axial dimension greater than an axial dimension of the seal portion.