Tractors and Agricultural MachineryTractors and Agricultural Machinery0321-44432782-425XEco-Vector6635510.17816/0321-4443-66355Research ArticleOptimization of traction characteristics of agricultural tractorsSamsonovV. ADSc in Engineering-LachugaYu. FAcademician of the Russian Academy of Sciencesmehelagro@mail.ruAutonomous non-commercial organization «Editorial Board of the journal «Mechanization and electrification of agriculture»Russian Academy of Science151120178411495627042021Copyright © 2017, Samsonov V.A., Lachuga Y.F.2017The productivity of the machine-tractor unit depends on the energy saturation of the tractor. It is assumed that the optimum traction characteristic corresponds to the minimum operating weight of the tractor and its maximum energy saturation, at which the maximum productivity of the machine and tractor unit is achieved with the lowest fuel consumption and compliance with restrictions on tractive effort, slippage and theoretical speed. As a criterion for determining the maximum energy saturation, the maximum efficiency coefficient is adopted with maximum tractive power and maximum tractive efficiency. Calculation of the optimal traction characteristics is an actual task of the theory of the tractor. The purpose of the study is to develop a methodology and algorithms for calculating the indicators of the optimal traction characteristics of the tractor when the engine speed of the crankshaft is changed. The objects of research are wheeled and caterpillar tractors of general purpose. Input data: engine and tractor performance indicators; coefficients that characterize the traction and coupling properties of the tractor; the tractor power balance equation; slipping functions; the dependence of the fuel consumption of the engine and its torque on the speed of the crankshaft. The method of research is the calculation using the basic formulas of the theory of the tractor when the speed of the crankshaft is changed by one rotation. Taking into account the accepted values of the nominal engine speed and the torque adaptive factor, the gear ratio is calculated. The calculation procedure for the optimum traction characteristic is developed for tractors with a minimum operating weight, calculated taking into account the nominal tractive effort and the coefficients of using the gravity of the tractors. The maximum energy saturation for each type and traction class of the tractor is determined by calculating the tractive characteristic of the transmission, at which the maximum efficiency factor, traction power and traction efficiency are reached. The main conclusion: the optimum traction characteristic corresponds to the minimum operating weight of the tractor and its maximum energy saturation.agricultural tractormaximum energy saturationoptimal traction characteristicsproductivityсельскохозяйственный трактормаксимальная энергонасыщенностьоптимальная тяговая характеристикапроизводительность[1. Самсонов В.А., Лачуга Ю.Ф. Расчет максимальной энергонасыщенности сельскохозяйственного трактора // Тракторы и сельхозмашины. 2017. № 10. C. 36-41.][2. Кутьков Г.М. Тракторы и автомобили. Теория и технологические свойства. М.: КолосС, 2004. 504 с.][3. Скотников В.А., Мащенский А.А., Солонский А.С. Основы теории и расчета трактора и автомобиля. М.: Агропромиздат, 1986. 384 с.][4. Описание основных узлов и технические характеристики трактора К-424 «Кировец». Режим доступа: http://kirovets-ptz.com/rus/i_dc1/ci_i/63/informatsiya_pro_k-4f__1_.pdf.][5. Двигатели ЯМЗ-536, ЯМЗ-5361, ЯМЗ-5362, ЯМЗ-5363, ЯМЗ-5364, их модификации и комплектации. Руководство по эксплуатации / Под ред. Н.Л. Шамаля. Ярославль: ОАО «Автодизель», 2013. 240 с.]