Increasing the smoothness of the course of the forage harvester by optimizing the mass-dimensional and inertial parameters of its body

A scientific and methodological rationale and practical recommendations for stabilizing the movement of forage harvesters are proposed. The calculation of the optimal weight and size and inertial parameters of the body, as well as the elastic properties of tires as the main element of the suspension system of the combine was theoretically justified. Using the developed methodology on the example of a prototype harvester, the possibility of calculating the optimal tire stiffness and the mass of additional counterweights installed at the machine is shown to ensure equality of the natural frequencies of the front and rear axles of the wheels on the elastic tire. Taking into account the mathematical and simulation model of the combine, which was developed by authors, its motion on a dirt road and asphalt highway with different speeds was modeled. To evaluate the effectiveness of the proposed method for improving ride smoothness, a comparison was made of the peak and root-mean-square values of the longitudinal angle of inclination of the body, as well as the levels of vertical vibration acceleration in the cab on the floor under the seat of the combine operator in its basic version and a modified version due to the use of counterweights of a given mass and with optimized tire stiffness. With the help of simulation modeling, an octave analysis of the vibration load of the workplace was performed. It is shown that in the main driving modes, optimization of the weight, size and inertial parameters of the body, as well as the elastic properties of the combine tires, improves the comfort of the operator’s workplace, especially in the most dangerous frequency range for humans. There are determined the modes of movement, which allow to achieve the best effect. The stabilization process is described. The conclusions for further research are presented.

forage harvester, counterweights, galloping, fluctuations, smoothness, vibration of the workplace