PROBLEM TO BE SOLVED: To provide a prime mover part structure of a work vehicle, which has high suction performance of a radiator fan and high exhaust performance of a dust discharge fan with less frequently of maintenance/inspection work.SOLUTION: The prime mover part structure of a work vehicle includes: a radiator fan 20 for outer air suction and a dust discharge fan 30 for exhaust, which are disposed between an engine E and a radiator 50 and can be switched between a drive state and a stop state an intermediate transmission part 150 to which drive force of the engine E is transmitted and a fan transmission part 160 to which the drive force is transmitted from the intermediate transmission part 150 and which drives the radiator fan 20 and the dust discharge fan 30. The intermediate transmission part 150 is located outside of a rotation locus of the radiator fan 20 when viewed in the radiator fan 20 rotation axis direction, and rotation power of the engine E is transmitted to the intermediate transmission part 150 from a portion on an opposite side to the radiator 50 with respect to the engine E in a crank shaft 60 of the engine E.
