Relay fan capable of cooling circuit board

Abstract

A relay fan capable of cooling a circuit board includes an air extraction motor, a heat dissipation base, and the circuit board. The air extraction motor includes an outer housing and a motor body. The outer housing has a first opening and a second opening opposite to each other, and the motor body is disposed in the outer housing. One end of the motor body has an exhaust outlet corresponding to the second opening. The heat dissipation base is disposed on the outer housing of the air extraction motor. The circuit board is electrically connected to the motor body of the air extraction motor and disposed on the heat dissipation base, and an airflow of the air extraction motor that is in an operation cools the heat dissipation base to further cool the circuit board.

What is claimed is: 
     
         1 . A relay fan being disposed outside of a range hood body, comprising:
 an air extraction motor including an outer housing and a motor body, wherein the outer housing has a first opening and a second opening opposite to each other, and the motor body is disposed in the outer housing; wherein one end of the motor body has an exhaust outlet corresponding to the second opening;   a heat dissipation base disposed on the outer housing of the air extraction motor; and   a circuit board electrically connected to the motor body of the air extraction motor and disposed on the heat dissipation base, such that an airflow of the air extraction motor that is in an operation cools the heat dissipation base, so as to cool the circuit board.   
     
     
         2 . The relay fan according to  claim 1 , wherein the outer housing further has a third opening corresponding to the heat dissipation base, and the heat dissipation base is sunken into the outer housing through the third opening. 
     
     
         3 . The relay fan according to  claim 2 , further comprising an outer cover covering a periphery of the circuit board, wherein at least one flow-guiding hole is formed on the outer cover. 
     
     
         4 . The relay fan according to  claim 3 , wherein the heat dissipation base is a metal heat dissipation base that is a rectangular hollow column, the heat dissipation base is partially sunken into the outer housing, and the heat dissipation base has a heat dissipation wall and two side openings; wherein the two side openings are located on two lateral sides of the heat dissipation wall, a plurality of heat dissipation holes are formed on the heat dissipation wall and in fluid connection with the two side openings, and the two side openings are connected to an interior of the outer cover and the at least one flow-guiding hole. 
     
     
         5 . The relay fan according to  claim 4 , wherein the outer cover includes two side cover plates that are opposite to each other, and each of the two side cover plates has the at least one flow-guiding hole formed thereon. 
     
     
         6 . The relay fan according to  claim 1 , wherein a pipe sleeve is disposed on the first opening of the outer housing, such that the first opening is connected to an air duct of the range hood body through the pipe sleeve. 
     
     
         7 . The relay fan according to  claim 1 , further comprising a relay transceiver electrically connected to the circuit board, wherein the relay transceiver is configured to amplify and transmit a relay fan activation signal sent by the range hood body when the range hood body is turned-on.