KINEMATIC ANALYSIS AND OPTIMAL DESIGN OF THE SEPARATION CONVEYOR DEVICE FOR PANAX NOTOGINSENG COMBINE HARVESTER

Abstract

Panax notoginseng is a high-value medicinal rhizome crop widely cultivated in the hilly and mountainous regions of southwest China, where traditional manual harvesting remains labor-intensive and inefficient. To address these challenges, this study focuses on the design, kinematic analysis, optimization, and validation of a separation conveyor device for a self-propelled Panax notoginseng combine harvester. The separation conveyor was developed based on the agronomic characteristics of Panax notoginseng and the mechanical requirements of soil-rhizome separation. A comprehensive methodology integrating theoretical modeling, kinematic and mechanical analysis, coupled discrete element-multibody dynamics (DEM-MBD) simulations using EDEM and RecurDyn, and laboratory experiments was employed. Key operational parameters, including conveyor speed, vibration frequency, and lifting angle, were systematically evaluated through quadratic regression and orthogonal experimental design. Simulation results indicated that effective soil separation could be achieved within 2.25 s, with fine soil particles separating earlier than larger aggregates. Laboratory tests identified optimal parameters of 0.8 m·s⁻¹ conveyor speed, 1.5 Hz vibration frequency, and a 20° lifting angle. Field validation experiments confirmed the reliability of the optimized design, achieving average separation and conveying rates of 96.87% and 96.42%, respectively, with a low rhizome damage rate of 1.88%. The results demonstrate that the proposed separation conveyor provides an effective solution for mechanized harvesting of Panax notoginseng and offers valuable reference for similar rhizome crop harvesters.