Device and method for comminuting bulk material grains

A device for comminuting bulk material grains, comprising:

• a first element having a first surface and a first receiving section,
• a second element with a second surface and a second receiving section,
• a feeding device,
• wherein the first surface and the second surface are arranged parallel and facing each other,
• the first element and the second element are movable back and forth, relative to one another, between a first position and a second position, and the direction of movement being in a plane defined by the first and second surfaces,
• in the first position, the first receiving section and the second receiving section communicate with each other, via a passage, and form a receiving area in which a grain of bulk material can be positioned via the feed device,
• when the first element and the second element are moved from the first position to the second position, a cross-section of the passage is narrowed,
• wherein the first element is formed as a rotor rotatably mounted about a rotor axis and having a cylindrical circumferential surface, the first receiving section is an at least partiallyformed circumferential groove, and the rotor has at least one axial groove crossing the circumferential groove, and the first surface is a side wall of the axial groove, and
• the second element is designed as a shear bar and is arranged in the axial groove so as to be movable back and forth along the axial groove, and the second receiving section being a recess of the shear bar;
• and
• wherein the shear bar is movable by means of a cam gear from the first position into the second position and/or from the second position into the first position, the cam a direction of rotation of the rotor at an axial end of the rotor, upon rotation of the rotor the control cam moves an axial end of the shear bar axially, the device further comprising at least one punch axially guided in a guide bore of the rotor, the punch being connected to at least one shear bar and being moved axially by the control cam upon rotation of the rotor.