Vibrations analysis of combine harvester seat in time and frequency domain

Agricultural machineries as one of the main inputs in producing agricultural materials are associated with some problems on occupational health such as vibrations. At the lowest level, vibrations cause different diseases such as those affecting blood vessels, nerves, muscles, etc. The aim of this study was to determine and investigate the seat vibrations in John Deere 1055I combine harvester at different conditions. The experiments were carried out based on ISO 2631 and the Iranian standard number 14133. The tests were done at different engine revolutions and gear ratios with three replications. The collected data were analyzed considering factorial experiments based on completely randomized design. The results of variance analysis related to the effect of the main factors on combine seat vibrations showed a significant difference at the probability level of 1%. Effect of engine revolutions on vibration of the combine seat was higher than that of shifting gears. By calculating the allowable exposure time, there was concluded that for the first and second gears at the engine revolution of 1800 rpm and the first gear at the revolution of 2500 rpm, operators can easily drive the combine harvester for eight hours every day without any problems. The results of this study can be used to optimize the components affecting the vibration of the combine seat