Design development and study of an elastic sectional screw operating tool

This study considers the interaction of soil particles with a screw tillage body, the working surface of which is made in the form of a deployed helicoid and substantially differs from the screw. Furthermore, the unfolded surface is characterised by manufacturability of the working body, since it is possible to calculate the geometric dimensions of a flat workpiece, which is formed into a finished product by simple bending with minimal plastic deformations. The purpose of this paper was to conduct theoretical and experimental studies of the movement of soil particles along the helical surface of the tillage working body, which is made in the form of a deployed helicoid. Mathematical modelling of the processes of movement of soil particles along the helical surface of a tillage working body was described based on general laws and principles of analytical and differential mathematics, theoretical and analytical mechanics. Experimental studies were carried out using a methodology with elements of mathematical statistics, mathematical methods of optimal planning of a multifactor experiment. The analysis of the results of experimental and theoretical studies was performed using applied computer programmes and systems. Experimental studies were conducted according to standard and independently developed methods. Results: a mathematical model of the movement of soil particles along the helical surface of the tillage body was developed, and it was established that when the angle of attack of the helical tillage working body increases, the lifting value of soil particles increases and the area of their dispersion by the helical surface increases. The value of the coefficient of friction does not substantially affect the shape of the trajectory of the soil particle. The quality of loosening the soil most depends on the angle of attack of the screw surface and the angular speed of rotation of the working body. The materials of this paper can be used by scientists for further research and practices in the selection of tillage units.

Study of the Movement of Soil Particles on the Surface of a Screw Tillage Working Body

Pylypaka¹,

Klendii²,

Kresan³

2022

Transportation of a material particle by the operating mechanism of an agricultural machine in the form of a vertical screw confined by a coaxial stationary cylinder

Pylypaka¹,

Klendii²

2022

The use of vertical augers in screw conveyors significantly expands the operational capabilities of such mechanisation equipment for performing loading and unloading technological operations. However, the existing designs of vertical screws do not fully meet the operational requirements. Their main disadvantages are increased energy consumption, especially with their significant overall dimensions, which depend on the influence of friction of the process material on the conveyor surfaces. Therefore, the study considers the movement of a material particle by the operating mechanism of an agricultural machine in the form of a vertical screw confined by a coaxial stationary cylinder and establishes the dependence of the speed of transportation of a material particle on the influence of the particle friction coefficient on the surface of the screw and on the surface of the limiting cylinder. The purpose of the study is to determine the parameters of the movement of agricultural material particles when they interact with the helical surface of the operating mechanism of a vertical conveyor in the form of a screw that rotates around the axis and the surface of a coaxial fixed cylindrical casing. Mathematical modelling of the processes of movement of soil particles along the helical surface of the operating mechanism is described on the basis of general laws and principles of analytical and differential mathematics, theoretical and analytical mechanics. As a result of the study, the differential equations of movement of a particle of agricultural material on the helical surface of the screw, which rotates around its axis in a fixed cylinder, were compiled. The equation is solved using numerical methods and the trajectories of the relative motion of the particle along the helical line – the edge of the screw, which is common to the surface of the screw and the limiting cylinder are constructed. The friction forces of the material particle on the surfaces of the screw and casing are also considered. The limit value of the helical line lifting angle is found when the particle lifting becomes impossible at a given angular velocity of screw rotation. The influence of the friction angles and radius of the limiting cylinder on the particle lifting speed is estimated. Graphs of kinematic characteristics as a function of time are given. The materials of the study can be used by researchers for further investigation and by practitioners in the selection of conveyors for transporting agricultural materials

Justification and calculation of design and strength parameters of screw loaders

Klendii¹,

Logusch²,

Dragan³

et al. 2022

Existing designs of screw working bodies of transport and processing machines cannot always provide the required performance and avoid overloading, which causes deformation and damage to parts of the mechanisms. Thus, it is necessary to establish new efficient screw working bodies that would ensure the execution of the technological process. The purpose of the study was to substantiate and explore the design and methodology for calculating the main structural-power parameters of the developed screw loader, to synthesise screw loaders using the method of morphological analysis to obtain designs of mechanisms with better technical and economic characteristics. The methods of surface theory, analytical and differential geometry, computer graphics and mathematics were used to conduct the research. As a result of theoretical and experimental studies, the designs of screw conveyors with hopper loading and screw conveyors with nozzle loading are presented. In addition, a classification of loaders for screw transport and technological mechanisms is presented. The dependencies for calculating the design of screw conveyor loaders are determined. The synthesis of loaders and mixers by the method of morphological analysis was performed to obtain designs of mechanisms with the best technical and economic characteristics and competitive designs of mechanisms were established. A system of coding and synthesis of structural elements and mechanisms of screw implements with improved technological properties is proposed, and competitive designs of screw implement that perform technological processes efficiently and effectively are selected. A methodology for calculating the main structural and power parameters of a screw loader has been developed, which allows for determining the parameters of a screw loader. The materials of the research can be used in further studies of screw conveyors and, in particular, screw loaders to determine their design, technological, energy and power parameters