Patent ID: 7584780

Claim:
A heat sink for heat generating devices comprising: a heat conducting body having a base plate for placement in heat conducting relationship with the heat generating device and a plurality of spaced apart heat conducting flow augmenting rings with at least one air pumping aperture between the rings; a main air flow passageway extending through said spaced apart rings and being sized to receive an axial fan with propeller blades extending towards a radially inward edge of the flow augmenting rings to deliver a main flow of air in an axial direction along said main air passageway toward the base plate and with a gap between the propeller blades and the inner radial edge of the rings selected to enable production of tip vortices from the propeller tips; and with average ring chordal dimensions being effectively selected with respect to a radial dimension of the main air flow passageway so as to enable tip vortices from the propeller blades to be converted to useful air flow along said axial direction with a radially inwardly induced secondary air flow between and over said heat conducting flow augmenting rings that is a significant portion of total mass flow generated along said main air flow passageway; at least one solid heat conducting column extending from said base plate to support said rings and being in heat conducting relationship therewith so as to transfer heat from the base plate to said heat conducting flow augmenting rings; the axial dimension of said air pumping aperture between axially adjacent heat conducting flow augmenting rings being selected so as to enable said tip vortices to extend into the aperture and impinge upon radially inner regions of the rings and produce a region on at least one of said rings having a heat transfer coefficient H c of at least about 50 Watts/m 2 /° C.; so as to impart to said heat sink with said flow augmenting rings a high overall heat transfer characteristic; whereby the thermal resistance of said heat sink, when combined with said axial fan within the main air flow passageway, is reduced to a sufficiently low level so as to significantly enhance the removal of heat from said heat generating device.