Effect of tires' pressure on the kinematic mismatch of a four-wheel-drive tractor

Abstract

In the article causes of kinematic mismatch of four-wheel-drive tractor were reviewed. One of the most important operating characteristics is the relationship between tire inflation and vertical load of the wheels. Due to changes in inflation pressure and tire load, variations in rolling radiuses of the front and rear wheels can cause power circulation in the tractor transmission. This power circulation is dependent on the difference between theoretical speeds of front and rear wheels. In the paper, dynamics of a four-wheel-drive tractor performing a rectilinear motion is analyzed. Power circulation between the front and rear driving axles is deter-mined, tacking into account slipping of the wheels. Then dynamic study is conducted to achieve power balance of tractor and put in evidence power circulation in longitudinal plan. Experiments were carried out to establish relationship between tires' inflation, vertical load and kinematic mismatch with theoretical speeds of driving wheels. The purpose was to determine the effect of additional slip on four-wheel-drive tractors operated without drawbar pull. Dependences of wheels' slippage and kinematic mismatch with theoretical speeds are presented.