MATHEMATICAL MODELING OF THE HYDRAULIC DRIVE OF THE SECTIONS OF A WIDE-COLLECTING CULTIVATOR WITH SEQUENTIAL ACTIVATION OF HYDRAULIC CYLINDERS

The publication discusses the issues of mathematical modeling of dynamic processes occurring in a complex hydromechanical system of the hydraulic drive of the wide-cut cultivator sections with consistent wear of the hydraulic cylinders. The analysis of known designs of wide-cutting tools and agricultural units is carried out. It is noted that one of the tendencies in the development of domestic agricultural engineering is an increase in the width of coverage of tillage machines. In this regard, hydraulic drives for decomposition and assembly of sections of these machines are widely used. The use of this type of drive is due to its compactness, speed and power. The basic schematic diagrams of hydraulic drives for decomposition of wide-cut tillage machines are considered. On the basis of the analysis, a schematic diagram of the hydraulic drive for assembling (decomposing) sections of a wide-grip cultivator with sequential actuation of hydraulic cylinders is proposed and the principle of its operation is described. A mathematical model has been developed for the hydraulic drive of the wide-grip cultivator sections in the working and transport position. The mathematical model consists of the equations of the continuity of the flows of the working fluid, which describe the processes occurring in the hydraulic drive, and the equations of moments and forces, from which it is possible to determine the force factors acting on the elements of the system. It is difficult to obtain an analytical solution to the resulting system of equations, therefore, to find solutions, numerous methods were applied, namely the Runge-Kutta-Feldberg method with an automatic change in the integration step. On the basis of the obtained dependencies, an analysis of the operation of the hydraulic drive with sequential wear of the hydraulic cylinders was carried out and recommendations were proposed on the design device and directions for improving the hydraulic drive of the tillage unit sections.

Design and computer simulation of automatically controlled hydromechanical system for looped wedge wire screen elements fabrication

The article presents a design of mechatronic system used for the production of wire elements used in looped wedge wire screen manufacturing. Details related to the design of the hydromechanical subsystem, the control subsystem, as well as the simulation of the operation process of the entire system are presented

Numerical Simulation of the Perforated Shell’s Oscillations in a Vibrational Priller

The widespread catalysts and nuclear fuel production are the sol-gel technology, including several stages, namely, the raw materials preparation, dispersing it into drops, the granules formation in gas and then in liquid media, granules removal with liquid separation. The vibration granulator is proposed to use on the dispersion stage. One of the problems in their development is determining the vibrational characteristics of a perforated bucket filled with liquid to a certain level. Considering that vibrations are transmitted from the emitter disk through the liquid melt and cause vibrations of the perforated shell, in research, it was decided to use the Fluent Flow and the Transient Structural modules of the ANSYS Workbench software. As a result, numerical simulation results of the emitter disk vibration effect on the cylindrical body are presented. Also, parameters of a discrete mathematical model are evaluated by the bucket vibrations characteristics. The corresponding model considers the inertial, stiffness, and damping properties of functional elements. Additionally, according to the modal analysis results of the priller body, it was determined the eigenfrequencies of the hydromechanical system. Finally, based on the numerical simulation results and their analysis using Fourier transformations, it was determined that the oscillations of the lower part of the bucket, consisting of two harmonic oscillations that equal 230 Hz and 520 Hz.

Study on oil pilot circuit of adaptive hydraulic drive of tool advance in mobile drilling machine

Introduction. An adaptive hydraulic drive of the tool advance in a mobile drilling machine is studied on the example of the URB-2.5 installation. A typical technological cycle of the mobile drilling machine is considered; the performance criteria are defined. An original design of the adaptive hydraulic drive is proposed on the basis of the analysis. Adaptation of the hydraulic drive of the tool advance is carried out using an adjustable volumetric hydraulic motor with a hydraulic control circuit under discontinuous loads on the tool during the drilling process.Materials and Methods. Through a preliminary computational experiment in the Matlab Simulink program, the following parameters of the control loop devices were determined: a hydromechanical sensor and a hydraulically controlled valve, on the basis of which the experimental setup was implemented. The performed multifactor experiment allowed identifying the processes in the original hydraulic control circuit of the hydraulic motor under various modes of tool loading.Research Results. The kinematic and power characteristics of the hydromechanical system of a mobile drilling rig, the hydraulic control effect on the settings of the hydraulic control circuit devices were obtained and determined. The results enabled to specify the rational ranges of the hydromechanical system operation for a typical work cycle.Discussion and Conclusions. The results obtained can be used to create hydraulic systems of new drilling machines with various characteristics. The application of the developed techniques of research and processing of their results will reduce the time and costs involved in designing adaptive hydraulic systems for mobile technological machines, creating prototypes and conducting commissioning procedures.

Mathematical model of the volumetric hydrodrive’s dynamics, sensitive to the loading variation

The paper deals with the problems of mathematical modeling of the dynamic processes proceeding in a complex hydromechanical system of the ship’s deck load-lifting devices. The characteristic feature of this class of equipment is the operation in special conditions, i.e, under the influence of external hydrometeorological factors, taking into account variations in the parameters of lifted or lowered cargo. With a view to gradual regulation of the change of torque on the working drum to reduce dynamic loads, it is offered to use a hydraulic drive that is sensitive to the variation of loading. The operating principle of the considered volumetric hydraulic drive is described. The received mathematical model allows to establish influence of the hydrodrive parameters on transients in a drive system.