Image Number 12 for United States Patent #7685816.
A cooling system for a construction machine, which can reduce noise of a cooling fan and can reliably produce cooling air at a required flow rate.The cooling system comprises a cooling fan 25 for producing cooling air introduced to an intercooler 22, a radiator 23 and an oil cooler 24, a fan hydraulic motor 26 for driving the cooling fan 25, a fan hydraulic pump 27 for delivering a hydraulic fluid to the fan hydraulic motor 26, an air temperature sensor 31 for detecting an air temperature T.sub.1 at an outlet of the intercooler 22, a cooling water temperature sensor 33 for detecting a temperature T.sub.2 of cooling water for the radiator 23, a working oil temperature sensor 36 for detecting a temperature T.sub.3 of working oil for the oil cooler 24, and a controller 29 for outputting a control signal corresponding to a maximum value among calculation values N.sub.1, N.sub.2 and N.sub.3 of cooling fan rotation speed, which correspond respectively to detected values T.sub.1, T.sub.2 and T.sub.3 from the air temperature sensor 31, the cooling water temperature sensor 33 and the working oil temperature sensor 36.
|
