Vibration Response of Combine Harvester Chassis Undergoing Multisource Excitation Force Distribution

When a combine harvester is harvesting in field under complicated conditions, vibration characteristics of the chassis frame under the excitation of multiple sources are complex and changeable. In order to analyze the vibration characteristics of the chassis frame of the combine harvester under complex working conditions and multisource excitation, this paper carried out three-dimensional modeling and static calculation of the chassis frame of the combine harvester. On this basis, the experimental modal analysis was carried out on the designed chassis frame, and finally, the vibration response under multiple excitations and complex working conditions was tested and analyzed in the field. Results showed that when the combine harvester was fully loaded, the maximum bending moment was at the load-bearing beam under the grain box. The maximum bending moment was 2298.08 N/m, and it was located at the cross section of the left end of the bearing beam at 1.61 m. When the components of the whole machine were working, the vibration of the chassis frame at the rear right was the most intense. The horizontal vibration of the threshing drum, the reciprocating motion generated by the vibrating screen, and the vertical vibration generated by the engine were the main vibration sources of the combine harvester in the three directions of X, Y, and Z. With the i\ncrease of engine speed, the excitation capacity of each working component connected to the engine on the whole machine increased. The results of this paper provide experimental basis for the research on the vibration characteristics of the chassis frame of the rice combine harvester under multisource excitation and also provide a reference for the further improvement of the chassis frame of the combine harvester.