To eliminate the need for increasing the horsepower of motive power by amplifying force of rotation depending on a load (resistance) on a rotating shaft.

The rotating power amplifying device amplifies force of rotation depending on rotating load (resistance), thereby maintaining a rotating speed without increasing the horsepower of motive power. On this purpose, a device is provided for changing rotating resistance into force, which is constructed to encircle the regular-pentagon rotating shaft 1 outside with a regular-pentagon external support.