The main working part of this is the rotor with a hammer (or hammer head), which consists of spindle, hammer and other parts. The motor drives the rotor spinning with high-speed in the cavity, and the materials needed to crush are conveyed into the cavity from the inlet, and being crushed by high-speed movement of the hammer blowing and impact, squeezing, and grinding among the materials. There is a screen plate at the bottom of the rotor, which can screen the crushed materials: materials size smaller than the sieve can come out through the sieve, while the materials with bigger size than the sieve will still be shot and grinded by the hammer, and finally be discharged out from the plate.