Agricultural harvester with improved rotor transition geometry

An agricultural harvester, comprising:

• a chassis;
• and
• a threshing and separating system carried by said chassis and configured for threshing and separating grain from gathered crop material, said threshing and separating system including:
• a rotor defining a longitudinal axis;
• a concave at least partially surrounding said rotor;
• a transition cone defining an infeed to said rotor;
• and
• a transition surface connecting said transition cone to said concave and having a conical portion defined about said longitudinal axis and a blended portion connected to said conical portion, said blended portion defining a first end connected to said conical portion and a second end distanced from said first end in a lateral direction, said blended portion defining a substantially conical shape about said longitudinal axis at said first end and approaching a substantially cylindrical shape about said longitudinal axis toward said second end, said transition surface having a transition length in a direction parallel to the longitudinal axis, the transition surface having a front and a back, the front of said transition surface at said first end of said blended portion having a diameter of said conical portion, the back of said transition surface at said first end of said blended portion having a cylindrical shape and a diameter, the diameter at the back of said transition surface at said first end of said blended portion being approximately equal to a diameter of the front of said transition surface at said second end of said blended portion.