Crop processing assembly for a combine harvester

A crop processing assembly comprising:

• a tube-shaped cage structure having an inlet section and an outlet section, and comprising a cover that forms an upper portion of the cage structure and one or more gratings which form a lower portion of the cage structure,
• a crop processing rotor that is rotatable about a central rotation axis, and that is mounted inside the cage structure, the rotor having a cylindrical outer surface, with threshing and separation elements mounted on said cylindrical surface, and with a gap between the outer surface of the rotor and an inner surface of the cover,
• wherein the cage structure and the rotor are configured so that the rotation of the rotor actuates the transfer of crops along a helicoidal path through said gap, from the inlet section to the outlet section,
• wherein the cover comprises a step between an upstream portion of the cover and a downstream portion of the cover, the step extending between a lower rim lying on the upstream portion and an upper rim lying on the downstream portion of the cover, so that at least in an upper part of the cover, said gap is larger in the downstream portion than in the upstream portion, and
• wherein in a parallel projection view of the cover, projected in a direction of a line that is perpendicular to the rotation axis of the rotor and passing through a central point of the upper rim of the step, the step is oriented at an oblique inclination angle (α) relative to a plane through said line and perpendicular to the rotation axis of the rotor, the inclination angle and a direction of inclination being configured so that the step is arranged to guide the crops passing from the upstream section of the cover to the downstream section.