Kinematics of the Tined Combine Harvester Reel

Abstract

Although derivation of the kinematic equations of the combine harvester reel is readily achieved, certain inferences thereof suggest possible improvements in its kinematical design.  A mathematically computed reference value of the reel index (ratio of the product of the reel radius and rotational velocity to the reel advance velocity) is found to be larger than commonly recommended values.  The point, either spatial or temporal, within the cycle of reel motion, at which the tinebar should preferably enter the crop is discussed.  The pick-up performance of the tines is qualitatively analyzed and its possible improvement through redesign of reel tine kinematics is suggested.

Keywords: combine harvester reel, reel kinematics, tine trajectory