Investigations on Winnowing Steps in the Combine Harvester

摘要

The capacity of the combine harvester and the use of rotating systems for the separation of grain from straw have been increasing. Due to these new systems the cleaning unit is loaded stronger with MOG (mate-rial other than grain) and becomes gradually the bottleneck of the combine harvester. Therefore, winnowing steps are used to improve the performance of the cleaning unit by strengthening the pre-segregation effect of the grain-chaff-mixture. The purpose of this study is to investigate the basic principles and the functionality of winnowing steps. Test results about the effect of several structural and operating parameters are reported in this paper.