Dual cooling fan system driven by single motor

Abstract

A fan system includes a motor; a driven fan, driven by the motor; and a dummy fan, freely rotatable around a bearing support shaft. The fans have blade rings at their external surfaces. The blade rings include gears, engaged with each other such that rotation of the driven fan rotates the dummy fan.

1 . A fan system, comprising:
 a motor;   a driven fan configured to be rotated by the motor; and   a dummy fan configured to be rotated by the driven fan;   wherein the fans are configured such that when the driven fan is not rotated by the motor, the fans are rotated by ambient air that is moving relative to the fans.   
   
   
       2 . The system as defined in  claim 1 , wherein a diameter of the dummy fan is larger than a diameter of the driven fan. 
   
   
       3 . The system as defined in  claim 1 , further comprising a radiator, wherein the fans are configured to blow air toward the radiator. 
   
   
       4 . The system as defined in  claim 3 , wherein the fans are attached to a fan cover provided at a front side of the radiator. 
   
   
       5 . A fan system, comprising:
 a motor;   a driven fan, driven by the motor and comprising a first blade ring at an external surface thereof; and   a dummy fan configured to rotate freely around a bearing support shaft, and comprising a second blade ring at an external surface thereof;   wherein the blade rings each comprise gears, such that the blade rings are engaged with each other, such that rotation of the driven fan rotates the dummy fan.   
   
   
       6 . The system as defined in  claim 5 , wherein the driven fan is disposed near a transmission, and the dummy fan is disposed near an engine. 
   
   
       7 . The system as defined in  claim 5 , wherein a ratio of a diameter of the driven fan to a diameter of the dummy fan is approximately 7:10. 
   
   
       8 . The system as defined in  claim 5 , wherein the driven fan comprises a first number of fan blades, and the dummy fan comprises a second, larger number of fan blades. 
   
   
       9 . The system as defined in  claim 8 , wherein the first number is 5 and the second number is 6. 
   
   
       10 . The system as defined in  claim 5 , wherein the fans each comprise fan blades comprising polyacetylene 66 or polypropylene. 
   
   
       11 . The system as defined in  claim 5 , wherein a gear ratio of the gears of the driven fan to the gears of the dummy fan is approximately 10:7. 
   
   
       12 . The system as defined in  claim 5 , wherein the blade rings comprise aluminum. 
   
   
       13 . The system as defined in  claim 5 , wherein the gears comprise aluminum.