Patent ID: 6220207
Filing Date: 2001-04-24
Classification: F01P,F02B,Y02T

Abstract:
A construction machine having an engine mounted in an engine room and an engine cooling system including a plurality of heat exchangers comprising a radiator to cool cooling water supplied to said engine and an oil cooler to cool hydraulic fluid supplied to hydraulic actuators, a cooling fan rotated by a rotary shaft driven by a crank shaft of said engine for inducing cooling air to cool said heat exchangers, and a suction duct provided upstream of said cooling fan and downstream of said heat exchanger for introducing said cooling air to the suction side of said cooling fan, said engine cooling system passing said cooling air through in the order of said heat exchangers, said suction duct, said cooling fan, and said engine, wherein:said cooling fan is one of a mixed flow fan and a centrifugal fan, and includes an impeller provided with a plurality of vanes, and a rotary shroud fixed to said impeller and rotated together with said impeller,said suction duct has a downstream end in the form of a cylinder,an opening diameter of said downstream end is smaller than an opening diameter at a suction-side end of said rotary shroud,said suction duct is arranged such that said downstream end is positioned inside the suction-side end of said rotary shroud in overlapped relation in such a manner that said downstream end is substantially parallel to said suction-side end, andan overlapping amount between the downstream end of said suction duct and the suction-side end of said rotary shroud in the axial direction is not less than 0 mm, but not more than 40 mm.