Influence of tyres characteristics and travelling speed on ride vibrations of a modern medium powered tractor Part I: Analysis of the driving seat vibration

In the present investigation a contribution is offered in order to improve the knowledge of the influence of both speed and tyre type on a medium power tractor vibrations. The vibrations transmitted from the ground to the driver's seat of a ballasted wheeled tractor of medium power, equipped with a front suspension axle and a suspended cab, have been measured and analyzed. Two different tyres, namely, types A and B, at two different forward speeds, 11.1 and 13.9 m s-1, have been experimentally tested, during the simulation of the front agricultural implements transportation on a rectilinear plane tract of a conglomerate bituminous closed track. This work has been done by applying standards recommended by ISO 2631/1, 1997. Results were obtained on the basis of the measurement of both the root-mean-square (RMS) acceleration and the frequency analysis, conducted for any axis on the tractor rear axle and on the operator seat. In particular, different results were obtained for the two tyres and along all the axes. Furthermore, the acceleration was not strictly proportional to the forward speed increases.