Truck with a buil in conveyor belt

The truck box has a conveying device with a conveyer arranged in an inner transport space of the trunk box, and another conveyer (24B) adjacent to the former conveyer. Each conveyer comprises a driven roller (33) driven by a driven device (28) that is coupled to the roller between the conveyors. The device comprises a belt (54) for connecting a driving component i.e. pinion (48), to a driven component i.e. sprocket (51), where the driving component is placed in an outlet of a gear motor (M). The driving component and the gear motor are arranged under a lower wall (23) of the truck box.