PROBLEM TO BE SOLVED: To provide a working machine in which power transmission from an engine to a radiator cooling fan is constituted by a rational structure and with a simple structure.SOLUTION: A working machine includes a drive unit for driving a radiator cooling fan based on the power of an engine 3. The drive unit includes two systems of power transmission mechanisms of a forward system power transmission mechanism capable of transmitting forward power in an endless turning band, and a reverse system power transmission mechanism capable of transmitting reverse power in another endless turning band. Also, the drive unit includes a forward and reverse selection mechanism 6 capable of alternatively selecting the power from either one of the power transmission mechanisms and transmitting the power to an input rotating body 72 of the radiator cooling fan.COPYRIGHT: (C)2015,JPO&INPIT【課題】エンジンからラジエータ冷却ファンへの動力伝達を合理的な構造で、構造簡単に構成する。【解決手段】エンジン3動力に基づいてラジエータ冷却ファンを駆動させる駆動装置を備え、駆動装置は、無端回動帯で正転動力を伝達可能な正転系動力伝達機構と、別の無端回動帯で逆転動力を伝達可能な逆転系動力伝達機構との二系統の動力伝達機構が備えられ、かつ、何れか一方の動力伝達機構からの動力を択一的に選択してラジエータ冷却ファンの入力回転体72に伝達可能な正逆転選択機構6が備えられた。【選択図】図6
