Combine crop conveying and feeding system

A combine feeding system that maintains a constant clearance between a header auger and a feeder comprising:

• a feeder housing comprising (i) a first housing wall extending from a front end of the feeder housing to a rear end of the feeder housing and (ii) a second housing wall extending from the front end of the feeder housing to the rear end of the feeder housing, the second housing wall being spaced away from and substantially parallel to the first housing wall;
• a drive shaft coupled to at least one of the first housing wall and the second housing wall, extending lengthwise between the first housing wall and the second housing wall proximate to a rear end of the feeder housing and configured to rotate around a drive shaft axis substantially perpendicular to the first housing wall and the second housing wall;
• a lower conveyor roller proximate to the front end of the feeder housing, coupled to at least one of the first housing wall and the second housing wall, extending lengthwise between the first housing wall and the second housing wall and configured to rotate around a lower conveyor roller axis substantially perpendicular to the first housing wall and the second wall;
• an upper conveyor roller located proximate to the front end of the feeder housing, coupled to at least one of the first housing wall and the second housing wall, spaced from the lower conveyor roller, extending lengthwise between the first housing wall and the second housing wall and configured to rotate around an upper conveyor roller axis substantially perpendicular to the first housing wall and the second housing wall;
• at least one chain configured to move over the drive shaft, the lower conveyor roller and the upper conveyor roller;
• at least one lower support arm coupled to the drive shaft and the lower conveyor roller and configured to pivot about the drive shaft axis;
• the at least one lower support arm pivots around the shaft axis to regulate a tension in the at least one chain without reducing a predetermined distance between an auger associated with the feeder housing and a front surface of the at least one chain.