ANALYSIS OF INFLUENCE THE VARIABLE MASS UNIT ON THE RUNNING SMOOTHNESS OF THE WHEELED TRACTOR

Abstract

The study of the smooth running of tractors is an aggregate indicator that takes into account the norms of ergonomics and operation of the vehicle. Therefore, studies of smoothness are appropriate and relevant. Of particular interest is the study of the movement of a wheeled tractor with trailed or semi-trailer tanks that are filled with liquid - due to the significant influence of the natural oscillations of the liquid during the movement of the tank. In this regard, the goal of this work arises - the analysis of the smoothness of the wheel tractor, which is coupled to a variable mass unit. In solving this goal, a technique was used that provided for mathematical modeling of longitudinal-angular vibrations of a wheeled tractor with a variable mass unit. Used model, which takes into account the redistribution of liquid in the tank caused by vibrations of the shell, using the characteristics of Rayleigh surface waves. An analysis of the smoothness of the wheel tractor was based on the determination of the vertical accelerations of the driver’s seat and tractor frame. As a result, theoretical research data were obtained that reflect the effect of fluid redistribution in a semitrailer tank on the smoothness of the wheel tractor. It was determined that when transporting liquid cargo, the effect on the smoothness of the wheel tractor is greater than when transporting solid cargo. It was also found that the shift of the resonance zone of the influence of the semitrailer unit on the vertical acceleration of the operator’s seat with varying filling heights of the tank is a quadratic function, namely a parabola. The practical significance of the work is to establish the influence of design indicators, namely the pressure in the pneumatic tires (tractor and tank), on the value of the smoothness of the tractor. Reducing the magnitude of the vertical acceleration of the operator's seat is achieved by reducing tire pressure. But with a decrease in tire pressure, it is necessary to take into account the change in the technical and economic indicators of the tractor. Therefore, a promising follow-up study, according to the author, is to address the issue of optimizing the reduction in the smoothness of the wheel tractor when driving with a semitrailer-tank in compliance with technical and economic indicators (fuel consumption, productivity, etc.).