Analysis and Testing of Straw Collector Crushing Mechanism Based on DEM-MBD Coupled Simulation

To address the low efficiency of corn straw collection, this study aims to optimize the design of the straw shredding mechanism of corn straw harvesters. A multi-blade arrangement shredding mechanism was designed, with ANSYS 2022 employed for gas-phase flow field simulation of the pick-up and fan conveying chambers, and a multi-field coupled simulation was conducted to evaluate performance using pick-up rate and qualified cutting length rate as metrics. Field tests were carried out to validate the simulation results. The results show that the DC-type pick-up (symmetrically arranged Y-shaped and hammer claw blades) exhibited optimal performance. At a travel speed of 1.2 m/s and rotational speed of 2100 r/min, the pick-up rate and qualified cutting length rate reached 93.62% and 93.94%, respectively, in field tests (81.34% pick-up rate in simulation); its maximum collection efficiency reached 92.98% under the conditions of fan 1 speed of 2300 r/min, fan 2 speed of 4600 r/min, and single feed rate of 9.4 kg. All pick-up types had maximum forces below the stress limit (348 MPa), meeting operational requirements. This research provides reliable references for the design and optimization of corn straw returning machines and verifies the accuracy of the simulation method.