The main unit is the main part of vertical roller mill, it’s the part for stone grinding and powder classifying,it’s the heart of the whole plant.The work process in the main unit as blow,
 
When the vertical roller mill is at work, the main bearing and each dial are driven by electromotor of main equipment through reducer, and all the grinding rollers are rolling in the ring channels driving by dial through plunger. The materials are driven to the edge of the turn plate by the centrifugal force and fall down into the grinding chambers where the materials are repeatedly pressed, crushed and grinded by the rollers. Then the materials fall into multiple layers and to be crushed and ground continuously to micro powder.
 
Main unit, classifier, powder collector, dust cleaner, blower, muffler, sound-proof room, crusher, bucket elevator, storage hopper, and vibrating feeder.are the main parts of HGM serials vertical roller mill including.

More detais of vertical roller mill, please see the links below,
 http://www.vertical-mill.net/mill/105.html