Disc chipper for crushing lumpy feed material, particularly wood

A disc chipper for comminution of lumpy feed material, the disc chipper comprising:

• a crushing rotor driven by a drive unit and rotating about a rotational axis;
• a rotor shaft;
• and
• a chipping disc connected in a rotationally fixed manner with the rotor shaft, a surface of the chipping disc having chipping knives that are transversely aligned in a disc plane to the rotational direction and that cooperate with stationary counter knives for the comminution of the feed material,
• wherein the rotor shaft has a bearing seat for the chipping disc, the bearing seat having a polygonal cross section, and the surface of the chipping disc having the chipping knives having a centric through-hole extending therethrough, the through-hole having a polygonal cross section that is complementary to and mates with the polygonal cross section of the bearing seat for a form-lock fit, and
• wherein the chipping disc has a weight of at least 5,000 kg.