Patent ID: 8068339

Claim:
An axial fan apparatus, comprising: an axial-flow impeller capable of rotating to effect a flow of gas to cool down one or more heat generators, the axial-flow impeller including a plurality of blades inclined with respect to a rotational axis direction; a drive unit that rotates the axial-flow impeller; and a housing mounted with the drive unit, the housing including an annular sidewall around the axial-flow impeller, the annular sidewall including a plurality of slits that enable the circulation of the gas, the plurality of slits being adjacently spaced, defined entirely within the annular sidewall, and inclined with respect to the rotational axis direction in a direction opposed to a direction in which the plurality of blades incline, the axial-flow impeller and the plurality of slits being configured to affect the flow of the gas to suppress noise produced by the axial-flow impeller, a mount plate extends from a lower portion of the annular sidewall for mounting the axial fan apparatus, wherein each of the plurality of blades includes an end portion at an outer circumferential side of rotation, a negative pressure generation surface that generates a negative pressure, and an auxiliary vane standing on the negative pressure generation surface at the end portion.