Comparative evaluation of the parameters of the traction characteristics of modern 4k4 roller tractors

The article considers the regularities of the influence of variable load on the performance of power packed tractors. The objects of the study were power packed roller tractors which are part of tillage units. When analyzing the results of calculations to establish the degree of influence of probabilistic load on tractor operation parameters, the following regularities were established. The underutilization of traction power for the three tractors under study is different and depends on the value of the adaptability coefficient by the momentum Kp . The underutilization of the traction power of a John Deere 8310R tractor (in the area of optimal loading λ м = 0.88-0.9) in the range of the coefficient of variation of traction force νp = 0-0.2 amounts to 8.6%. In the rated power mode, the Nen power loss amounts to 9.5%. With a large value of the coefficient of variation νp , a slight increase in specific fuel gpi consumption was established. The level of power losses is not high, this is due to the value of the adaptability coefficient of the momentum Kp = 1.4. The analysis of the design data for the tractor K-744R2 showed that the reduction in traction power is more significant with 17-18% (with νp = 0.2). The reason for this high percentage of power loss is the low factor = 1.21. Specific fuel consumption in the area of nominal mode according to the design data is increased by 10%. Underexploitation (decrease) of traction power of K-424 “Кirovets” tractor in the field of the nominal traction force Ppi end νp at a value of 0.15-0.2 reaches 9-10%, i.e. from 171 kW to 158 kW. Specific fuel consumption increases with a value of νp > 0.1. One of the reasons for such a decrease in tractor power K-424 is an insufficiently high momentum margin according to modern standards (according to the data of the manufacturer, the coefficient Kp = 1.35). Comparison of the presented data indicates a greater adaptation to the effect of variable load of tractors with a diesel engine having a Kp factor > 1.25.