Integrated blower diffuser-fin heat sink

Abstract

An air-cooled heat exchange device for cooling an object such as an electronic device generating heat during use. The device includes a toroidal electric motor with a centrifugal blower for directing air flow in a downward and outward direction, a heat sink positioned to receive the air flow from the blower; and a spiral diffuser as part of the heat sink, the diffuser having vanes for directing the air flow spirally over the heat sink. The vanes may include microfabricated vibrating reeds and a plurality of microfabricated dimples on at least some of the vanes.

1 . An air-cooled heat exchange device for cooling an object, comprising:
 a centrifugal blower for directing air flow in a downward and outward direction;   a heat sink base positioned to receive the air flow from the blower; and   a diffuser on the heat sink base and in the path of the air flow from the blower, the diffuser having vanes that are in thermal communication with the heat sink base and that direct the air flow from the blower outward over the heat sink base.   
     
     
         2 . The device of  claim 1 , where the object being cooled is an electronic device generating heat during use, the electronic device being positioned in contact with the heat sink. 
     
     
         3 . The device of  claim 1 , wherein the centrifugal blower is driven by a torriodal electric motor and the downward direction is through the center of the motor. 
     
     
         4 . The device of  claim 1 , wherein the diffuser further includes secondary vanes in the air flow channels defined by the vanes to prevent flow separation and increase heat transfer surface area. 
     
     
         5 . The device of  claim 1 , wherein the vanes comprise a diffuser set of vanes forming air flow channels above the heat sink extending spirally out from the center of the heat sink. 
     
     
         6 . The device of  claim 1 , wherein the diffuser further includes vibrating reeds in the vane channels defined by the vanes. 
     
     
         7 . The device of  claim 6 , wherein the vibrating reeds include a piezoelectric component and means for actuating it to cause the reeds to vibrate. 
     
     
         8 . The device of  claim 1 , which further includes a plurality of microfabricated surface features on at least some of the vanes to increase heat transfer area per unit volume. 
     
     
         9 . The device of  claim 8  where the plurality of microfabricated surface features are dimples. 
     
     
         10 . The device of  claim 1 , wherein the centrifugal blower extends downward into and is surrounded by the diffuser. 
     
     
         11 . The device of  claim 10 , wherein the centrifugal blower includes an upper hub, a lower hub, and a plurality of blades connected between the upper hub and the lower hub. 
     
     
         12 . The device of  claim 11 , wherein the lower hub includes a port for allowing passage of air downward through the lower hub into a space between the lower hub and the heat sink base. 
     
     
         13 . The device of  claim 11  and further comprising a toroidal electric motor mounted on the diffuser and having a stator, a rotor, and a central air passage, the rotor being connected to the upper hub of the centrifugal blower. 
     
     
         14 . A method of cooling an object using an air-cooled heat exchanging device, comprising the steps of:
 directing air flow in a downward and outward direction using a blower; and   directing the air flow through a diffuser in thermal communication with a heat sink base positioned to receive the air flow from the blower and directing it outward over the heat sink base.   
     
     
         15 . The method of  claim 14 , wherein the object being cooled is an electronic device generating heat during use, the electronic device being positioned in contact with the heat sink. 
     
     
         16 . The method of  claim 14 , wherein the centrifugal blower is a torroidal electric motor and the downward direction is through the center of the motor. 
     
     
         17 . The method of  claim 14 , wherein the diffuser vains comprises a set of vanes forming air flow channels above the heat sink extending radially out from the center of the heat sink. 
     
     
         18 . The method of  claim 17 , which further includes secondary vanes on the outer ends of the vanes to prevent separation of airflow and increase heat transfer surface area. 
     
     
         19 . The method of  claim 17 , which further includes vibrating reeds in the flow channels. 
     
     
         20 . The method of  claim 19 , wherein the vibrating reeds include a piezoelectric component for causing the reeds to vibrate. 
     
     
         21 . The method of  claim 17 , which further includes a plurality of microfabricated surface features on at least some of the vanes to increase heat transfer area per unit volume. 
     
     
         22 . The method of  claim 21  where the plurality of microfabricated surface features are dimples.