Fin assmebly and heat dissipation device using the same

Abstract

A heat dissipation device includes a centrifugal fan and a fin assembly aside the centrifugal fan. The centrifugal fan includes a casing and an impeller received in the casing, the casing defines an air outlet at one side thereof. The fin assembly is located at the air outlet of the centrifugal fan. The fin assembly includes a plurality of fins parallel to and spaced from each other. Each of the fins includes a main body and an extending portion extending form the main body toward the air outlet of the centrifugal fan. Each extending portion includes a side edge facing the air outlet of the centrifugal fan, the side edge is arc shaped and inwardly concaved toward the main body.

What is claimed is: 
     
         1 . A fin assembly comprising a plurality of fins defining a plurality of channels therebetween, each channel comprising an inlet for airflow entering the fin assembly and an outlet for airflow exhausting the fin assembly, each fin comprising:
 a main body; and   an extending portion extending from the main body, the extending portion comprising a side edge at the inlet of the channel, the side edge being arc shaped and concaved inwardly towards the outlet.   
     
     
         2 . The fin assembly of  claim 1 , wherein a pair of flanges bends horizontally from a top and a bottom of the main body, each flange being abutted with a flange of a neighboring fin, a first airflow passage being formed between every two adjacent fins. 
     
     
         3 . The fin assembly of  claim 1 , wherein the fins comprises two first fins and a plurality of second fins arranged between the two first fins, each of the second fins defining a through hole, the through holes cooperatively defining a second airflow passage. 
     
     
         4 . A heat dissipation device, comprising:
 a centrifugal fan comprising a casing and an impeller received in the casing, the casing defining an air outlet at one side thereof; and   a fin assembly located at the air outlet of the centrifugal fan, the fin assembly comprising a plurality of fins parallel to and spaced from each other, each of the fins comprising a main body and an extending portion extending form the main body toward the air outlet of the centrifugal fan, each extending portion comprising a side edge facing the air outlet of the centrifugal fan, the side edge being arc shaped and inwardly concaved toward the main body.   
     
     
         5 . The heat dissipation device of  claim 4 , wherein each fin defines a pair of notches at a top and a bottom portion of the extending portion to engage with the centrifugal fan. 
     
     
         6 . The heat dissipation device of  claim 5 , wherein the casing comprises a top cover, a bottom plate, and a sidewall connecting the top cover with the bottom plate, the top cover, the bottom plate and the sidewall cooperatively defining a receiving space for receiving the impeller, the notches of the fin engaging with the top cover and the bottom plate of the centrifugal fan. 
     
     
         7 . The heat dissipation device of  claim 4 , wherein a pair of flanges bend horizontally from a top and a bottom of the main body, each flange being abutted with a flange of a neighboring fin, a first airflow passage being formed between every two adjacent fins. 
     
     
         8 . The heat dissipation device of  claim 7 , wherein the fins further define a second airflow passage perpendicular to the first airflow passage. 
     
     
         9 . The heat dissipation device of  claim 8 , wherein the fin assembly comprises two first fins and a plurality of second fins arranged between the two first fins, each of the second fins defining a through hole, the through holes defining the second airflow passage. 
     
     
         10 . The heat dissipation device of  claim 9 , wherein the through hole is arranged away from the centrifugal fan. 
     
     
         11 . The heat dissipation device of  claim 6 , wherein the extending portions of the fins extend into the casing of the centrifugal fan. 
     
     
         12 . The heat dissipation device of  claim 11 , wherein the extending portions of the fins are sandwiched between the top cover and the bottom plate. 
     
     
         13 . A heat dissipation device, comprising:
 a centrifugal fan comprising a casing and an impeller received in the casing, the casing defining an air outlet at one side thereof; and   a fin assembly located adjacent to the air outlet of the centrifugal fan, the fin assembly comprising a plurality of fins parallel to and spaced from each other, each of the fins comprising a main body and an extending portion extending form the main body toward the air outlet of the centrifugal fan, each extending portion having a height less than that of the main body.   
     
     
         14 . The heat dissipation device of  claim 13 , wherein the extending portion and the main body of each of the fins are coplanar with each other. 
     
     
         15 . The heat dissipation device of  claim 13 , wherein the extending portions of the fins extend into the casing of the centrifugal fan. 
     
     
         16 . The heat dissipation device of  claim 14 , wherein the extending portion of each of the fins comprises a side edge facing the air outlet of the centrifugal fan, the side edge being arc shaped. 
     
     
         17 . The heat dissipation device of  claim 13 , wherein the fins comprise two first fins and a plurality of second fins arranged between the two first fins, each of the second fins defining a through hole adjacent to a lateral side thereof away from the centrifugal fan. 
     
     
         18 . he heat dissipation of  claim 17 , wherein the holes of the fins are arranged in line and cooperatively define an airflow passage extending along a direction perpendicular to a channel defined between each two adjacent fins.