Determination of the maximum pressure on the soil of agricultural tires with different ballasting methods of tractor

Abstract

The theoretical analysis of the maximum pressure on the soil of tractor tires with different methods of tractor ballasting is presented. The mathematical model of an empty and liquid ballasted agricultural tire is presented. Problem. As the standards of the running systems of mobile agricultural machinery on the soil limit the maximum pressure of wheeled tractors on the soil, there is a contradiction between high traction efficiency and harmful effects on the environment. The goal of the research is to perform a comparative analysis of the maximum tire pressure on the soil with two methods of increasing the tractor's weight: by installing cast iron ballast and filling the tires with ballast liquid. In solving the final goal, a methodology that provided the analytiсal methods for evaluating the effect of the tire filling with ballast fluid on its stiffness, load capacity and the area of contact area with the soil, is used. As a result it has been found that the tire stiffness increases by 3.5–5.5% when filled with 75% and practically does not change when filled with 40% by liquid ballasting. Cast iron ballasting is a versatile way to increase tractor weight, with maximum soil pressure 4.5–6.5% lower than tire liquid filling. Options for 75% and 40% liquid ballast for the use of water and calcium chloride solution as ballast liquid are considered. The originality of the work is to determine the maximum pressure on the soil of the agricultural tire ballasted with liquid and to compare it with traditional cast iron ballasting by the level of maximum pressure on the topsoil. The practical value of the work is, at the stage of designing or upgrading the wheeled tractor, to provide recommendations on possible method of the tractor ballasting, taking into account the agro–environmental requirements for maximum soil pressure.