Mathematical Model and Analysis of the Crushing Rate of Combine Harvester

Crushing rate is one of the key indicators to evaluate combine harvester operating quality. During the harvesting, crushing rate could be affected by factors like crop status, operation parameters, working condition and so on. Aiming at identifying the influencing factors and minimizing the crushing rate effectively, a mathematical model of the crushing rate was established through four-factor and three-level field experiments in this paper. The optimum operation parameters of combine harvester were identified through range and variance analysis. The field experiment results showed that the effect level of the four factors was: moisture content > threshing cylinder rotation speed > operation speed > concave clearance. Through simulating the optimization equation, the best parameter combination under the field experiment condition was obtained: 6 km/h - operation speed, 900 r/min - threshing cylinder rotation speed, 15 mm - concave clearance, 14.4 % - moisture content and 0.72 % - crushing rate as the minimum value.