Open AccessTHEORETICAL BACKGROUND OF CREATING A MATHEMATICAL MODEL OF TRACTOR TRACTION EFFICIENCY
Author(s) -
Kamil Khafizov,
Kamil Khafizov,
Ramil Khafizov,
Ramil Khafizov,
Азат Нурмиев,
Азат Нурмиев,
Ilgiz Galiev,
Ilgiz Galiev
Publication year - 2019
Publication title -
vestnik kazanskogo gosudarstvennogo agrarnogo universiteta
Language(s) - English
Resource type - Journals
ISSN - 2073-0462
DOI - 10.12737/article_5db9748fc053c2.28431294
Subject(s) - tractor , traction (geology) , slipping , automotive engineering , engine power , rolling resistance , coefficient of friction , traction power network , ground pressure , skid (aerodynamics) , power (physics) , environmental science , mathematics , mechanical engineering , structural engineering , materials science , engineering , physics , composite material , quantum mechanics
To identify the main parameters of the tractor - its mass, engine power, wheel diameter and its profile width (four-parameter optimization) using the optimization criterion - the total energy costs (taking into account the energy of the crop lost due to the non-optimality of these parameters), it is necessary to have a mathematical model for calculation of engine power through the traction coefficient of performance of the tractor. The traction efficiency of the tractor is calculated through f is the coefficient of resistance to rolling of the tractor wheel and d is the coefficient of slipping of the tractor wheel. An analysis of the applied theory developed by previous researchers showed that the values f and d depend on the weight of the tractor coming to one wheel G, the diameter D and the width of the profile of the wheel B, the pressure in its tires ρw, the hardness of the soil H, the effort on the tractor hook Pkp and its speed V. During the analysis, it was found that the larger the diameter of the wheel, the width of the tire profile, the less the vertical load on the wheel and the pressure in the tires, the less the resistance to rolling the wheel over the soil being compacted. It is concluded that the study of the nature of the change in the coefficient of resistance to rolling wheels f and their slipping d from the above factors must be carried out jointly, because they influence each other. The absence of acceptable mathematical dependences for calculating the indicated coefficients, with the simultaneous action of all identified factors, leads to the need for a seven-factor experiment to identify the dependencies f =j (G, D, b, ρw, H, Ркр, V) and δ =ψ (G, D, b, ρw, H, Ркр, V), which is very difficult in operating conditions, therefore, using the similarity theory, it is necessary to reduce the number of factors in the experiment to four.