DOI: 10.7256/2453-8809.2018.4.22014

Abstract: The authors consider the procedure of building mathematical models of stability of mechanical systems functioning as described in Lyapunov theory used for solving the tasks of agricultural mechanics. The authors describe the results of agricultural machines operation analysis. The authors build the dependencies which can help define soil pulverization angle for various tillage depths based on the given parameters. These dependencies help define the parameters of dynamical systems reducing their energy consumption, improving qualitative indicators and creating the conditions for equipment performance improvement. The described model of the physical essence of wedge-soil interaction process is widely used for solving various tasks of justification the parameters of tilling mechanisms. However, the physical essence of processes occurring in the tilled soil layer under the influence of a wedge has not been studied sufficiently enough. When using any stability theory, it is important to define ultimate strain values causing material deformations leading to the destruction of the initial structure. Ultimate stress values can be easily defined by experiment only for stretching strain and compressional strain. Consequently, to define the strains occurring in soil under the influence of wedge, we can accept a hypothesis that a tilled soil layer splits away from the elastic mass by bending.  

DOI: 10.7256/2453-8809.2017.4.26797

Abstract: The subject of the study is the ways to increase the efficiency of transport vehicle and traction vehicle with dual wheels in different modes of operation (transport, working, traction). The object of the study is the system of twin wheels with the ability to adjust the area of contact with the soil for operation in different operating modes. The state of the soil in the process of its re-consolidation by the running part of mobile agricultural machinery clearly indicates a close correlation between the change in the mechanical, technological, biological, chemical, morphological properties and economic indicators of the soil state, and, consequently, the level of environmental safety of used mobile agricultural machinery, including the composition of soil cultivating units. The research methodology is based on analysis and synthesis, generalization of practical experience, graphic representation of the information received. The urgency of the study is determined by the need to ensure environmental safety, soil conservation, increase the fertility of agricultural land in the modern world. The scientific novelty is that the use of dual wheel systems with the ability to adjust the contact area with the soil for operation in different operating modes will make it possible to abandon the use of expensive caterpillar thrusters.

DOI: 10.7256/2453-8809.2017.3.24563

Abstract: The object of the research is the process of a work tool of a tillage machine with a flexible element getting into contact with the soil. The subject of the research is a physical model that allows to analyze the process of a work tool with a flexible element getting into contact with the soil and mechanical and technological methods of improving the process of soil cultivation. The cable with a cross section area in a form of a circle is viewed as a wedge with a dull edge. The authors of the article pay special attention to the theory of granular medium statics. The extreme limit state at which even the slightest change in the volume and surface forces distorts the balance of the granular medium is especially interesting and useful for composing mathematical models of a work tool getting into contact with theh soil because pressure forces reach the highest point at such moments. The authors carried out their theoretical research using the method of the mathematical mechanical modelling of work tools getting into contact with the soil. The authors discover the dependence of the wedge cutting pressure on the cutting angle and depth. They prove that when the cutting angle is reduced, the cutting pressure of the soil goes down to the minimum at first but grows endlessly afterwards. The soil cutting effort is composed of two elements, the soil destruction effort and the effort to overcome the frictional force of the soil against the wedge. When the cutting angle is reduced, the soil destruction effort decreases while the effort to overcome the frictional force of the soil against the wedge increases. The sum of these two elements is equal to the minimal effort of the wedge cutting the soil. 

DOI: 10.7256/2453-8809.2017.2.23150

Abstract: The research object is the process of functioning of the excavating parts of a cultivating separating ripper, which transforms the structure and the density of a soil layer in accordance with the requirements of agronomical science for the cultivated crop. This result is achieved using the coordinated interaction of passive and active excavating parts. The machine also combs out the weed. The author considers the plowshare with steering disks, which spends less energy when moving through soil and directs soil to the separator. Theoretical researches are based on mechanical and mathematical modeling of interaction of the moving parts with soil. Experimental researches are based on the sectoral methods using strain-gage instruments and the methods of multifactor experiments planning. In the result, the process of soil cultivation using disk cultivating parts has been improved, the theory of justification of the parameters of active-passive cultivating parts for the separation and pulverization of soil and been developed; the mathematic model of interaction of cultivating parts with soil with account of energy intensity rates of technological processes has been composed. The use of methods of direct variational calculation for the justification of shapes of cultivating parts of a cultivating separating ripper helps reduce energy consumption by 10-30%. 

DOI: 10.7256/2453-8809.2017.1.22037

Abstract: The research subject is the process of movement of soil along the plowshare of a cultivating separating ripper – a stratification machine. The article contains particular constructive features of the implements used for cutting and elevating soil, quality and energy indexes of their operation. The author defines the estimation criteria for the development of a relatively new solution to the problem of secondary tillage effectiveness. The author describes the technological process of operation of a cultivating separating ripper with additional leading passive plane rotary disks, which ensure appropriate movement of soil along the shovel at the cultivation depth of 3-12 cm. The author considers in theory and analyzes the impact of some constructive factors on quality indexes of the implements used for soil cutting and elevating. The scientific novelty consists in usage of parallel free-rotating plane disks together with the plowshare at the same time. The author acquires the values of angle of soil friction and elevation by the plowshare giving the minimum resistance of the plowshare. In the result, the mechanical elevation and movement of soil along the plowshare of a cultivating separating ripper doesn’t give a building up effect and requires minimum energy.