Study on the Conveying Characteristics of a Hanged Harvester Vibrating Screen for Ligusticum Chuanxiong

Abstract

The problem of soil and Chuanxiong tuber congestion on vibrating screens usually exists during the Chuanxiong mechanized harvesting process. To address this problem, the conveyance performance of a crankshaft rocker vibrating screen was studied. By establishing and solving the dynamics and kinematics equations for the crankshaft rocker vibrating mechanism and Chuanxiong soil residue, the acceleration of the vibrating screen and Chuanxiong-soil residue was studied. The sliding speed, motion process, and conveying distance of the Chuanxiong soil residue were also analyzed. The theoretical analysis results indicated that the acceleration of the vibrating screen depends on the rod lengths of the vibrating mechanism and the crank rotational speed and position. The displacement of the Chuanxiong-soil residue along the positive sliding direction in a cycle was more significant than that of the negative sliding direction. The appropriate advancement speed of the harvester was also obtained. The RecurDyn and EDEM coupling simulation was conducted. The simulation results verified the theoretical analysis. In the simulation, the Chuanxiong-soil residue was effectively conveyed. The field tests were conducted to verify the theoretical analysis. The harvester was tested in the field with crank rotational speeds of 0 r/min, 120 r/min, and 240 r/min, and advancement speeds of 0.5 m/s, 1 m/s, 1.5 m/s, and 2 m/s. The results showed that there was no congestion in the screen during the working process when the rotational speed of the crank was 240 r/min, and the advancement speed of the harvester was no faster than 1.5 m/s. When the crank rotational speed was 240 r/min, and the advancement speeds were 0.5 m/s, 1 m/s, and 1.5 m/s, the weights of Chuanxiong and soil on the screen after the test were 71.5 kg, 84.7 kg, and 105.7 kg, respectively. The field tests verified the conveyance performance of the vibrating screen. This study can provide a theoretical reference for designing the crankshaft rocker vibrating mechanism for the rhizome harvesting machine.