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2019, N 1 (35) |
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TECHNOLOGIES AND FARM MECHANIZATION MEANS
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Berezhnov N. |
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Selection and justification of the tractor parameters when aggregating with a machine for strip loosening of soil |
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The article discusses the results of studies conducted to determine the compliance of traction-speed performance of the tractor included into the composition of machine-tractor unit to the requirements of aggregation, taking into account the random nature of changes in the external operating factors. Field tests of machine-tractor unit Fendt 936 Vario + AVA-12,6 "Agropitatel’" was conducted in the conditions of the farm enterprise "V.S. Pecherin" in Leninsk-Kuznetsk district of the Kemerovo region in 2017. The method of control dynamometry established probabilistic characteristic of traction resistance of agricultural machines, its dependence on their speed of movement at primary tillage operation. The tests were conducted on medium-humus podzolized chernozem soil at stubble background in depth of tillage 16 and 21 cm and the average run of cultivated land 1130.2 m. The given values of traction resistance of the machine-tractor unit (at speed of 5 km/h) were 2.99 and 5.04 kN/m, respectively. The coefficient of proportionality on operation of tillage is 0.057 and 0.034 s2/m2, and the variation coefficient - 10.5 and 2.1%. The data were obtained at a significance level of 0.05. It is established that the tractor Fendt 936 Vario does not meet the requirements for working speed and propulsion skidding while operating at averages specific traction resistance within the range of 2.38≤M(k0)≤5.25 kN/m. The calculated average value of the required nominal rated power of the engine of the aggregate power unit is 350.5 kW (476 hp.), so the required operational weight for the unit to perform the loosening operation is 201.8 kN. The aggregate power unit with the calculated parameters will provide an increase in traction efficiency by 4.4% in comparison with the Fendt 936 Vario tractor; it leads to an increase in the average working traction on the hook by 10.5%, implemented without violating the established requirements. It results as an increase in the average operating speeds of the machine-tractor unit by 20% and an increase in its net hourly productivity by 18.4%.
Keywords: TRACTOR, RIPPER, DYNAMOMETRY, AGGREGATE, TRACTION RESISTANCE, SKIDDING, FIELD TESTS, COUPLING WEIGHT, PARAMETER, STATISTIC |