Patent ID: 9388827
Filing Date: 2016-07-12
CPC Classification: F04D

Claim Text:
1. A blower fan comprising: a stationary portion; a bearing portion; and a rotating portion supported by the bearing portion to be rotatable with respect to the stationary portion; wherein the rotating portion includes: the stationary portion includes: edges of the side wall portion at both ends of an opening of the side wall portion, an edge of the upper plate which extends between the edges of the side wall portion, and an edge of the lower plate which extends between the edges of the side wall portion are arranged to together define an air outlet; an inside surface of the bearing portion, an outside surface of the shaft, and a lubricating oil arranged in a radial gap defined between the inside surface of the bearing portion and the outside surface of the shaft are arranged to together define a radial dynamic pressure bearing portion arranged to generate a fluid dynamic pressure in the lubricating oil; axially opposed surfaces of the bearing portion and the rotating portion and the lubricating oil arranged in a thrust gap defined between these surfaces are arranged to together define a thrust dynamic pressure bearing portion arranged to generate a fluid dynamic pressure in the lubricating oil in the thrust gap; the lower plate includes a lower air inlet arranged to pass through the lower plate in the vertical direction, and arranged radially outward of the bearing portion; the upper plate includes an upper air inlet arranged to pass through the upper plate in the vertical direction; an inside surface of the side wall portion includes a tongue portion where a radial distance between the inside surface of the side wall portion and any of the blades is shortest; in a plan view, a plane is divided into four regions by a first straight line which is parallel to the air outlet and crosses the central axis and a second straight line which is perpendicular to the air outlet and crosses the central axis, and one of the four regions in which the tongue portion is arranged is a first region, followed by a second region, a third region, and a fourth region in this order in a rotation direction of the blades; the air outlet is arranged to extend over both the first and fourth regions; at least a portion of the lower air inlet is arranged in the fourth region; and a radial distance between the central axis and a radially outer edge of the lower air inlet is arranged to be longest in the fourth region, wherein a circumferential position of a point on an edge of the upper air inlet where a distance between the edge of the upper air inlet and the central axis is longest in the fourth region is arranged to axially coincide with a circumferential position of a point on the radially outer edge of the lower air inlet where a distance between the radially outer edge of the lower air inlet and the central axis is longest in the fourth region.