PURPOSE: To make a crusher highly efficient by amplifying output of a motor of the crusher.

CONSTITUTION: An eccentric magnification driving gear with a large diameter 22 is engaged with a driving gear with a small diameter 21 driven by an output shaft 13a of a motor 13 of a crusher 13. When the eccentric magnification driving gear is connected to an epicyclic gear 28 of an epicyclic mechanism, torque of the driving gear is amplified and transmitted to the epicyclic gear. Amplified output from the output side of the eipcyclic mechanism functioning as a driven part is transmitted to the driving shaft to the crushing mechanism.