Теоретичне дослідження коливальних рухів гичкозбиральної машини, встановленої спереду агрегатуючого трактора

Abstract

Goal. To increase the quality of gathering and reliability of the top-gathering machine by minimizing the amplitude of its angular oscillations during movement on the unevenness of the soil surface. Methods. Theoretical studies were carried out using the basic principles of higher mathematics and theoretical mechanics, in particular the dynamics of a mechanical system. Numerical calculations and graphical dependences were obtained using a PC with the help of the developed and standard programs. Experimental studies were carried out according to standard methods of field multivariate experiments. Results. Based on the developed equivalent scheme of the frontally attached to the wheeled tractor top-gathering machine, the differential equation of the angular oscillations of the top-gathering machine to the center of instantaneous rotation of the tractor attachment mechanism was compiled. The analytical solution of this equation was obtained thanks to the law of oscillatory motion of the top-gathering machine in the longitudinal-vertical plane. As a result of numerical calculations, graphical dependences were built of the angle of rotation of the top-gathering machine at different speeds of its translational movement and different values of the coefficient of stiffness and damping of the tires of the copying wheels, as well as at different values of the main design parameters of the machine and the step of the unevenness of the soil surface. Conclusions. To reduce the amplitude of the angular oscillations of the harvester in the longitudinal vertical plane, its supporting wheels should be located as far as possible from the instantaneous center of rotation of the tractor’s front attachment mechanism. The central thrust of this mechanism should also be installed at the greatest possible angle of inclination to the vertical. The greater the step of the unevenness of the soil surface, the more stable will be the movement of the front-mounted top-gathering machine in the longitudinal-vertical plane. According to experimental studies, with amplitudes of oscillations of the lower ends of the knives of the rotary cutting device up to 5 cm, the loss of the sliver is insignificant. However, when the amplitude of these fluctuations increases to 7 cm or more, these losses become more significant and their maximum values can reach more than 12%.