The limited separation efficiency of potato-soil separation equipment in the southern potato planting areas is attributed to the high viscosity of the soil. To enhance the performance of the lifting chain separation device, a concave bar was designed. Structural parameters influencing the efficiency of potato-soil separation by bars were determined through kinetic analysis during the separation and transportation of potato-soil mixtures. Both a potato simulation model and a sticky soil simulation model were developed. Simulation tests indicated that the concave bar outperforms the straight bar in separation efficiency. Key factors investigated include the angle of the concave side, the width of the concave bar, the depth of the concave bar, and the installation angle. Orthogonal simulations were conducted using separation efficiency and the maximum force on potatoes as evaluation metrics. The results demonstrated that with a concave side angle of 15 degrees, a concave bar width of 450 mm, a concave bar depth of 60 mm, and an installation angle of 30 degrees, the separation efficiency of the potato-soil mixture reached 79.7%, with a maximum force on potatoes of 35.218 N, achieving the highest separation efficiency. Based on these results, test devices were constructed, and field tests were performed. The field test results showed a damage rate of 1.58%, a potato epidermal injury rate of 1.03%, and a loss rate of 2.87%. These results comply with national standards and validate the reliability of the simulation findings.

Aiming at the potato soil separation device of potato harvester, which generally has the problem of potato high damage in potato-soil separation, a three-stage potato soil low-loss separation device was developed, and orthogonal experiments were designed with the help of RecurDyn-EDEM coupled simulation method. A field bench was built for verification tests. The test proved that: when the lift transport chain speed was 1.40 m/s, travel speed was 0.60 m/s, amplitude was 32.0 mm, the impurity rate was 1.49% and the average force on potato was 1.801 N. The potato damage rate was 2.7%, indicating that the design of the three-stage potato soil low-loss separator device worked well.