To provide a novel driving force method by using a conventional gasoline engine or an electric motor or the like as a drive source.

A rotating shaft 17 provided with tanks 1 and 2 including fluid at both ends is disposed on the east side, and a rotating shaft 18 of similar constitution is disposed on the west side. Both rotating shafts are rotated reversely to each other. When the tanks 1 and 4 of the shafts approach fluid receiving cups at the same time, fluid in the tanks is discharged to the fluid receiving cups, so that centrifugal force is generated at the tanks 2 and 3 on the opposite side of the respective shafts to make driving force.