Estimation of agro cross-country ability indicators of powerful grain harvesters completed with tires of various designs

The introduction of new mobile energy devices of high performance supposes the development of various methods for increasing their traction and coupling properties and indicators of agrotechnical cross-country ability. The purpose of the paper is to determine the indicators of agrotechnical cross-country ability of the running systems of the mobile power equipment provided with tires with their different inner part. The object of the research is the process of interaction between the soil base and the vechiles of agricultural mobile energy resources. The research method is a theoretical and experimental research method using «a tire tester» and a complex of equipment, which provided the measurement of all necessary indicators of impactingmobile power equipment on the soil. It has been established that when equipping the running systems ofmobile power equipment with experimental tires, the agrotechnicalflotation ability of the mobile power equipment is improved. An experimental tire has an area of contact with soil base which is 16,65% higher than the serial one, and it is 7,38% higher than a radial tire, that has optimal parameters of the inner part. The values of maximum and average pressures according to GOST 26953-86 on the soil base are the smallest (by 11-28%) for tires of experimental design in comparison with other options. Mobile power equipment showed a lower pressure value with a soil base when being equipped with a 30,5E-32 experimental tire, but the subsurface soil at a depth of 50 cm reveals almost the same pressure for all the studied options. It is established that GOST 26955-86 requires clarification for various structural tire sizes and on different soil backgrounds: the negative impact of the running systems of the mobile power equipment on the soil should be estimated by both maximum and residual normal pressures. It is recommended to install tires of the proposed design on new powerful mobile power equipment.