The rock crusher has hammers mounted to a rotor and anvils mounted to its casing. First and second anvil sets define a convex surface arrangement facing the rotor and second and third anvil sets define a concave surface arrangement facing the rotor. The anvil sets are oriented to reduce compaction of rocks in the infeed portion of the crusher, and to reduce compaction of aggregate in the casing of the rock crusher. In relation to the movement of each hammer along their work sector, the two operations mentioned above are carried out before a third portion of the work sector wherein rocks are directed to rebound and impact the hammers head-on along the work circle of the hammers. The rock crusher is directly driven by the engine of a potato harvester, wherein the engine, the fan of the harvester and the rock crusher share a common inertia.
