Patent ID: 8210241

Claim:
A heat sink fan comprising: a heat sink including a base portion centered on its center axis and a plurality of fins arranged on an outer peripheral surface of the base portion and extending outward from the base portion in a radial direction perpendicular to or substantially perpendicular to the center axis; a fan arranged above and coaxial with the heat sink and including an impeller rotatable about the center axis to generate an axially downward air flow, a motor rotating the impeller, and a housing surrounding the impeller and supporting the motor, the impeller including a plurality of blades which are arranged about the center axis and extend outward in the radial direction, wherein the housing includes: a substantially annular surrounding portion; a plurality of support posts extending axially upward from the surrounding portion; a plurality of protrusions protruding downward from the surrounding portion, at least one of the plurality of protrusions being arranged directly under at least one of the plurality of support posts such that a portion of the at least one of the plurality of protrusions is provided at a same circumferential position of the surrounding portion as the at least one of the plurality of support posts; and a plurality of arms extending axially downward, the plurality of arms being provided with a plurality of engagement portions arranged to engage with the heat sink to restrict axial movement of the heat sink; at least one of the plurality of arms includes an attachment portion with a mounting member arranged to attach the heat sink fan to another device, an axially uppermost portion of the mounting member being higher than an axially uppermost portion of the heat sink; and the plurality of fins include a plurality of recesses arranged on lower surfaces of the plurality of fins and arranged to engage with the engagement portions.