Cooling System With Dual Reversing Fans

Abstract

A cooling system comprises a first cooling package, a second cooling package, and a fan control system. The first cooling package comprises a first fan and at least one heat exchanger to cool at least one fluid associated with the machine. The first fan is configured to rotate in a cooling direction and an opposite cleaning direction. The second cooling package comprises a second fan and at least one heat exchanger to cool at least one fluid associated with the machine. The second fan is configured to rotate in a cooling direction and an opposite cleaning direction. The fan control system is configured to alternate the first and second fans between a first cleaning mode and a second cleaning mode.

What is claimed is: 
     
         1 . A cooling system for a machine, comprising:
 a first cooling package comprising a first fan and at least one heat exchanger to cool at least one fluid associated with the machine, the first fan configured to rotate in a cooling direction and an opposite cleaning direction,   a second cooling package comprising a second fan and at least one heat exchanger to cool at least one fluid associated with the machine, the second fan configured to rotate in a cooling direction and an opposite cleaning direction, and   a fan control system configured to alternate the first and second fans between a first cleaning mode and a second cleaning mode, wherein, in the first cleaning mode the first and second fans concurrently rotate respectively in their cleaning and cooling directions advancing air in a first flow direction from the first fan to the second fan past the at least one heat exchanger of each of the first and second cooling packages, and, in the second cleaning mode the first and second fans concurrently rotate respectively in their cooling and cleaning directions advancing air in a second flow direction opposite the first flow direction from the second fan to the first fan past the at least one heat exchanger of each of the first and second cooling packages.   
     
     
         2 . The cooling system of  claim 1 , wherein the fan control system is configured to alternate successively the first and second fans between the first cleaning mode and the second cleaning mode during an exchanger-cleaning event. 
     
     
         3 . The cooling system of  claim 1 , wherein in the first cleaning mode the fan control system is configured to command operation of the first fan at at least a predetermined reverse speed threshold for a predetermined period of time, and in the second cleaning mode the fan control system is configured to command operation of the second fan at at least the predetermined reverse speed threshold for the predetermined period of time. 
     
     
         4 . The cooling system of  claim 3 , wherein in each of the first and second cleaning modes the predetermined period of time is cumulative excluding time that the respective first or second fan spends below the predetermined reverse speed threshold. 
     
     
         5 . The cooling system of  claim 3 , wherein the fan control system is configured to abort reversal of the first fan upon occurrence of an abort event, and is configured to begin reversal of the second fan when a speed of the first fan reaches a zero fan speed or at the end of a predetermined period of abort time if the speed of the first fan is below a low-speed threshold. 
     
     
         6 . The cooling system of  claim 1 , wherein the fan control system is configured to alternate successive exchanger-cleaning events between the first cleaning mode and the second cleaning mode. 
     
     
         7 . The cooling system of  claim 1 , wherein the fan control system is configured to operate the first and second fans sequentially in the first cleaning mode, an interim cleaning mode, and the second cleaning mode during an exchanger-cleaning event, and, in the interim cleaning mode, the first and second fans concurrently rotate respectively in their cleaning directions. 
     
     
         8 . A machine comprising the cooling system of  claim 1 , wherein the first and second cooling packages are positioned on laterally opposite sides of a fore-aft axis of the machine such that the first and second flow directions are laterally opposite to one another. 
     
     
         9 . The machine of  claim 8 , wherein the at least one heat exchanger of the first cooling package and the at least one heat exchanger of the second cooling package are positioned laterally between the first and second fans. 
     
     
         10 . The machine of  claim 9 , wherein the machine is a work vehicle.