Bearing apparatus, motor, and blower fan

摘要

A bearing apparatus according to a preferred embodiment of the present invention includes a bearing portion having a bottom and being substantially cylindrical; a shaft inserted in the bearing portion, and arranged to rotate about a central axis relative to the bearing portion; a bearing opposing portion defined in one piece, arranged above the bearing portion, and arranged to hold an upper end portion of the shaft while covering an outer circumferential surface upper portion and an upper end surface of the shaft; and a cylindrical seal portion arranged to extend downward from the bearing opposing portion. An inner circumferential surface of the cylindrical seal portion and an outer circumferential surface of the bearing portion are arranged to together define a seal gap therebetween, the seal gap including a seal portion having a surface of a lubricating oil defined therein.

主权项

1. A bearing apparatus comprising:
a bearing portion having a bottom and being substantially cylindrical; a shaft inserted in the bearing portion, and arranged to rotate about a central axis relative to the bearing portion; a bearing opposing portion defined in one piece, arranged above the bearing portion, and arranged to hold an upper end portion of the shaft while covering an outer circumferential surface upper portion and an upper end surface of the shaft; and a cylindrical seal portion arranged to extend downward from the bearing opposing portion; wherein an inner circumferential surface of the cylindrical seal portion and an outer circumferential surface of the bearing portion are arranged to together define a seal gap therebetween, the seal gap including a seal portion having a surface of a lubricating oil defined therein; an inner circumferential surface of the bearing portion and an outer circumferential surface of the shaft are arranged to together define a radial gap therebetween, the radial gap including a radial dynamic pressure bearing portion arranged to radially support the shaft; and the lubricating oil is arranged in a gap defined between a lower surface of the bearing opposing portion and an upper surface of the bearing portion, the cylindrical seal portion includes:
a cylindrical seal base portion defined integrally with the bearing opposing portion, and arranged to extend downward from the bearing opposing portion; anda cylindrical seal bushing fixed to an inner circumferential surface of the seal base portion; and the seal gap is defined between an inner circumferential surface of the seal bushing and the outer circumferential surface of the bearing portion.