While crusher working, the rotation of motor make forcible sway through by triangle belt, belt pulley, shaft coupling, transmission shaft and eccentric cover, and then make the broken taper ‘s broken wall close and leave the firm white wall surface sometimes, make ore bear constantly impact, pinch and then to realize ore broken. When there are no-broken stuffs or overloads for a certain reason, spring insurance system will start itself, output opening will be extended, and unusual stuffs will be discharged from crushing room. Under the function of the spring, the output opening will reset automatically, the machine resumes normal. This crusher can be classified into rough type, moderate type and careful fine type. The customer can make choice according to different requirement.