Motor and disk drive apparatus

摘要

A rotary unit of a motor includes a tubular hub portion. A bearing mechanism of the motor includes a bearing portion positioned radially inward of the hub portion. A stationary unit of the motor includes a stator fixing portion positioned inward of the hub portion and higher than a lower end of the hub portion. A cylinder gap is defined between the hub portion and an upper section of the bearing portion. A first communication gap is defined between a lower section of the hub portion and an upper section of the stator fixing portion. A second communication gap is defined between the lower end of the hub portion and a radial inner section of the stator core.

主权项

1. A motor, comprising:
a stationary unit; a rotary unit; and a bearing mechanism arranged to support the rotary unit so as to rotate with respect to the stationary unit about a center axis extending in an up-down direction; wherein the rotary unit includes a cover portion extending around the center axis, a cylindrical sidewall portion extending downward from an outer edge of the cover portion, a tubular hub portion protruding downward from the cover portion at a radial inner side of the sidewall portion and a rotor magnet fixed to an inner circumferential surface of the sidewall portion; the bearing mechanism includes a shaft portion extending downward from the cover portion along the center axis and a bearing portion to which the shaft portion is inserted, the bearing portion being arranged to support the shaft portion through a lubricant, the bearing portion including an upper section positioned radially inward of the hub portion; the stationary unit includes a stator positioned radially inward of the rotor magnet, a base portion positioned below the stator and a stator fixing portion having a substantially cylindrical shape to extend upward from a central portion of the base portion, the stator fixing portion including an upper end positioned inward of the hub portion and higher than a lower end of the hub portion; the stator includes a stator core and a plurality of coils; the stator core includes an annular core-back arranged below the hub portion and a plurality of teeth portions extending radially outward from the core-back; each of the teeth portions includes a coil winding portion wound with each of the coils and a slanted portion positioned between the core-back and the coil winding portion to extend radially outward and upward; a seal region in which a boundary surface of the lubricant is provided is defined between the upper section of the bearing portion and the rotary unit; a substantially cylindrical cylinder gap is defined between an inner circumferential surface of the hub portion and an outer circumferential surface of the upper section of the bearing portion; a first communication gap is defined between a lower section of the hub portion and an upper section of the stator fixing portion, the first communication gap including a section extending in an axial direction or inclined radially outward and downward; and a second communication gap is defined between the lower end of the hub portion and a radial inner section of the stator core, the second communication gap extending radially outward from the first communication gap.