Demko O. Improving of combine harvesters technical and technological efficiency

The thesis is dedicated to improving combine harvesters productivity by means of efficient utilization of technical and technology factors with control of grain losses behind threshing and separation unit. Published papers analysis revealed that scientists left out of sight research of efficient utilization of technical features inhered in the combine harvesters design, including engine load, threshing through output capacity and energy performance factors: specific threshing power consumption, fuel consumption per one tone of grain and one hectare harvested, mechanical grain losses behind the combine harvester. Theoretical research allowed to determine influence of technical and technological factors (uneven yield spread, agronomy condition of cereals plants) on threshing throughoutput and, respectively, on performance and its derivative – grain losses behind threshing and separation. Dependence of combine harvester working speed and threshing load and engine load was analytically determined. Integral method for defining threshing throughoutput was developed, influence of yield fluctuations across the field area on threshing throughoutput and engine torque change was researched as well as dependence of specific mechanical grain losses behind threshing and separation from combine harvester output. For the first time role and importance of mechanical grain losses behind threshing and separation when determining combine harvester efficiency. Established that numerical mechanical losses values change depending of agronomic characteristics of grain mass. Medium numerical mechanical losses values can be described by variation coefficient within Kv=0.3–0.8 and when maximum values are reached working speed must be reduced. Established that combine harvester efficiency improvement staying within permitted grain losses parameters is possible by increasing threshing throughoutput and increasing engine load by 20–30 %, at the same time reducing specific fuel consumption per harvested tone and hectare.