Efficiency coefficient of tractor wheel drive while moving on ground

Abstract

Purpose. The purpose of the study is to improve the energy efficiency of tractors when working on a deformable support surface by increasing the efficiency of the wheel drive due to the rational selection of its parameters. Methods. The methods of the theory of movement of traction vehicles and theoretical mechanics are used. Results. Analytical equations are compiled that describe the dependence of the interaction of wheels with pneumatic tires with the ground support surface. The effect of tangential soil compliance on the efficiency of a single wheel and wheel drive was determined, and the influence of soil compliance was taken into account to determine the rational distribution of torque (traction) moments between the driving axles of a two-axle tractor. Conclusions 1. As a result of the conducted research, the dependence of the coefficient of useful action of the tractor's wheel drive on the coefficient of distribution of torque (traction) moments between the axles during movement on a deformable support surface was determined. The resulting mathematical model takes into account both the circular stiffness of the tires of the driving wheels and the flexibility of the soil in the contact patch. 2. The rational (optimal with the adopted mathematical model) value of the torque distribution coefficient βm between the axles should vary depending on the rolling resistance of the driving wheels and the characteristics of the soil background. With an electric drive of the driving wheels, adjustment of the coefficient βm is possible, and with a mechanical drive of the driving wheels, control of the coefficient βm can be carried out by adjusting the ratio of torsional stiffnesses of the tires of the front and rear wheels due to their internal pressure. 3. For agricultural tractors it is advisable to adjust the air pressure in the tires for each bridge separately, depending on the type of running system(4K4a, 4K4b) and the physical condition of the soil. Keywords: wheel drive, two-axle tractor, coefficient of useful action, deformation of the support surface, traction moments.