| 摘要 |
PURPOSE:To use a radiator effectively extending from low speed running to high speed running by connecting an oil path extending from a circulating pump and an oil path extending from an oiltight chamber to a common radiator to conduct cooling according to an output engine speed. CONSTITUTION:An oil path between a port 158 and a check valve 160 and an oil path between a port 159 and a check valve 161 are connected to an oil path 164 through a shuttle valve 163. The shuttle valve 163 is operated in such a manner as to communicate one of the ports 158, 159 which has higher oil pressure with the oil path 164. Therefore, oil is conducted to an oil tank 162 through a radiator 166. Accordingly, in the radiator 166, when the output engine speed is low, the oil absorbing heat generated in a hydraulic pump P is mainly cooled, and when the output engine speed is high, oil from oil tank 162 is mainly cooled. Thus the radiator 166 is effectively used extending from low output engine speed to high output engine speed. |
