| 摘要 |
A lower plate includes a lower air inlet arranged radially outward of a bearing portion. In a plan view, a plane is divided into four regions by a first straight line which is parallel to an air outlet and crosses a 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 a 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. |
| 主权项 |
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:
a shaft arranged to extend along a central axis extending in a vertical direction, and inserted in the bearing portion;a blade support portion arranged radially outward of the shaft, and arranged to rotate about the central axis together with the shaft; anda plurality of blades arranged in an annular shape radially outside the blade support portion, and arranged to rotate about the central axis together with the shaft; the stationary portion includes:
a lower plate arranged to cover the blades from below, and arranged to hold the bearing portion directly or indirectly;an upper plate arranged to cover the blades from above; anda side wall portion arranged to cover the blades from radially outside, and having a lower end portion fixed to the lower plate; 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. |
