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.

主权项

1. A bearing mechanism comprising:
a stationary portion including a shaft portion extending along a central axis extending upward and downward, and a plate portion extending to a radial direction outer side from the shaft portion and having an annular or substantially annular shape; and a rotating portion that includes a sleeve which is rotatable around the shaft portion, wherein the sleeve includes:
an annular portion that has an annular or a substantially annular shape;a cylindrical portion that extends from an outer edge of the annular portion toward an upper side;
an annular bottom surface that widens from an inner circumferential surface of the cylindrical portion to a radial direction inner side; anda first communication hole that includes an opening which is open to the annular bottom surface, and penetrates the annular portion in an axial direction, the rotating portion includes:
a ring member that is arranged to cover at least a portion of the opening of the first communication hole, and faces the plate portion via a first gap;an outer circumferential surface of the plate portion faces the inner circumferential surface of the cylindrical portion via an upper capillary seal portion whose gap in a radial direction is narrowed toward a lower side;a lubricating oil is interposed in a space between the stationary portion and the rotating portion, which includes:
the upper capillary seal portion;the first gap;a second gap between an outer circumferential surface of the shaft and an inner circumferential surface of the sleeve; andthe first communication hole; a pumping groove array, which is configured to cause the lubricating oil move to a radial direction inner side when the rotating portion rotates, is disposed in the plate portion or the ring member; a second communication hole, which is a gap widening in the radial direction and connected to the first communication hole, is disposed between the ring member and the annular bottom surface; and at least a portion of an opening of the second communication hole is positioned on the farther radial direction inner side than the pumping groove array.