PROBLEM TO BE SOLVED: To provide a service vehicle prime mover structure capable of ensuring the high draw-in capability of a radiator fan and the high exhaust capability of a dust discharge fan, suppressing the overheat of an engine, and ensuring the less frequency of maintenance and inspection work.SOLUTION: The object is attained by providing a radiator fan (20) and a dust discharge fan (30) on the same axis, providing driven state switching means (45) alternately switching over between the radiator fan (20) and the dust discharge fan (30) such that one is in a driven state whereas the other is in a non-driven state, disposing an oxidation catalyst device (11) oxidizing unburned fuel contained in exhaust gas discharged from an engine (E) above the engine (E), providing a rotary shaft (24) passing through a cylindrical rotary shaft (34) supporting the dust discharge fan (30) and supporting the radiator fan (20), and disposing the rotary shaft (24) above a vertical center of the radiator (50).
