COOLING DEVICE FOR A HEAT EXCHANGER

摘要

A cooling device for a heat exchanger that can be used in a heat exchanger for an engine for use in a hydraulic shovel. The cooling device comprises a fan that is driven by an engine and a shroud for accommodating the fan. The fan is of an axial flow type and the shroud has a bellmouth shaped fan surrounding portion. With respect to the shape of the fan surrounding portion, a value for a covering ratio (L4/L3) that is defined based on the relative positional relationship between the fan surrounding portion and a blade width is set so as to fall within a range of 41 to 70 percent. By using an axial flow type fan, it is possible to reduce the axial horse power of the fan, and by setting the covering ratio, it is possible not only to reduce the fan noise but also to improve the volume of cooling air.