scholarly journals Simulation of loading dynamics and hydrodynamics of drives of forest machine working bodies

2021 ◽  
Vol 875 (1) ◽  
pp. 012060
Author(s):  
N Yu Yudina ◽  
R V Yudin ◽  
A I Maksimenkov
Keyword(s):  
Hydraulic System ◽  
Hydraulic Drive ◽  
Pressure Change ◽  
Hydraulic Cylinder ◽  
Inertial Forces ◽  
Hydraulic Motor ◽  
Process Dynamics ◽  
Dynamic Factors ◽  
Working Bodies ◽  
Body Loading

Abstract The need to take into account the dynamic processes that occur when performing technological operations using the working bodies of forest machines with a hydraulic drive is due to the fact that its absence leads to a distortion of the obtained results, since the kinematic schemes do not take into account the influence of hydraulic fluid in the elements of the hydraulic system. In this regard, it became necessary to develop models that take into account the dynamics of working body loading and the hydrodynamics of its drives. It is recommended to consider the influence of the process dynamics by introducing dynamic factors. The resulting mathematical model allows you to determine the actual values of the hydraulic cylinder, taking into account the errors associated with fluid leakage. As a result of the study, it was possible to connect the pressure change in the hydraulic cylinder, the movement of the pistons in the hydraulic cylinder and the rotor of the hydraulic motor, as well as the appearance of inertial forces. The connecting component is the balance of fluid and hydraulic system volumes.

Stabilization of the Speed of the Hydraulic Motor Through Throttle Compensation for Volume Losses

2020 ◽  
Vol 26 (3) ◽  
pp. 126-130
Author(s):  
Krasimir Kalev
Keyword(s):  
Flow Rate ◽  
Hydraulic Drive ◽  
Pressure Change ◽  
Operating Conditions ◽  
Drive System ◽  
Inlet Pressure ◽  
Schematic Diagram ◽  
Hydraulic Characteristics ◽  
Hydraulic Motor ◽  
Flow Through

AbstractA schematic diagram of a hydraulic drive system is provided to stabilize the speed of the working body by compensating for volumetric losses in the hydraulic motor. The diagram shows the inclusion of an originally developed self-adjusting choke whose flow rate in the inlet pressure change range tends to reverse - with increasing pressure the flow through it decreases. Dependent on the hydraulic characteristics of the hydraulic motor and the specific operating conditions.

scholarly journals Theoretical background of hydraulic drive control system analysis for testing piston hydraulic cylinders

2019 ◽  
Vol 19 (3) ◽  
pp. 242-249 ◽  
Author(s):  
A. T. Rybak ◽  
I. K. Tsybriy ◽  
S. V. Nosachev ◽  
A. R. Zenin
Keyword(s):  
Mathematical Modeling ◽  
Hydraulic System ◽  
Energy Recovery ◽  
Test Bench ◽  
Hydraulic Drive ◽  
Mechanical Transmission ◽  
Hydraulic Motor ◽  
Hydraulic Machines ◽  
Life Tests ◽  
Hydraulic Cylinders

Introduction. The durability and performance of hydraulic machines is determined through life tests. At that, various braking devices (mechanical, electric, hydraulic, etc.) are used for strength loading of the hydraulic motor, as a result of which a significant amount of energy is lost. This can be avoided if the method of rotational motion with energy recovery is used during life tests. This approach is applicable for hydraulic pumps, motors, and hydraulic cylinders.Materials and Methods. A test bench is presented, the design of which provides recreation of the conditions most appropriate for the field operation of hydraulic cylinders. In this case, energy recovery is possible. To solve the research problems, methods of mathematical modeling were used, the basic functional parameters of the proposed design were calculated. The determination of the pressure increment at various points in the hydraulic system is based on the theory of volumetric rigidity. When modeling the motion of the moving elements of the bench hydraulic system, the laws of rotor motion are used.Research Results. In the structure of the test bench, the cylinders in question are located in the pressure main between the hydraulic pump and the hydraulic motor. This enables to significantly reduce the bench itself and to save a significant amount of energy due to its recovery. A basic hydraulic diagram of the test bench for piston hydraulic cylinders is presented, in which the operation of the moving elements of the system is shown. A mathematical modeling of the hydraulic system of the bench is performed. A kinematic diagram of the mechanism for transmitting motion between test cylinders is shown.Discussion and Conclusions. The system of equations presented in the paper shows how the increment of pressure at the selected nodal points of the energy recovery system is determined (in particular, how the increment depends on time, reduced coefficient of volumetric rigidity, operating fluid consumption, and piston areas). The velocities of the hydraulic pistons are determined according to the kinematic scheme of the mechanical transmission of the bench. Thus it can be argued that, thanks to the solution presented in the paper, the life test results of hydraulic cylinders will adequately reflect their operation under rated duties.

scholarly journals Justification of the Kinematic Diagrams for the Distribution System of a Planetary Hydraulic Motor

2018 ◽  
Vol 7 (4.3) ◽  
pp. 6 ◽  
Author(s):  
Angela Voloshina ◽  
Anatolii Panchenko ◽  
Oleg Boltynskiy ◽  
Igor Panchenko ◽  
Olena Titova
Keyword(s):  
Distribution System ◽  
Hydraulic System ◽  
Hydraulic Drive ◽  
Fluid Distribution ◽  
Working Fluid ◽  
Hydraulic Motor ◽  
Hydraulic Motors ◽  
Output Characteristics ◽  
Kinematic Diagram ◽  
The Impact

The output characteristics of a planetary (orbital) hydraulic motor could be significantly improved if the kinematic diagrams for its working fluid distribution system are chosen correctly and substantiated. Fluctuations in the flow of the power fluid cause pulsation in the cavity of the input pressure of the hydraulic motor. This results to vibration of the hydraulic system elements. Thus, the hydraulic motor can be considered as a source of pulsation which leads to functional failures of the hydraulic system. As they run at low rotational speeds with high torque, planetary hydraulic motors are commonly applied for a hydraulic drive in active working tools of self-propelled machinery. It has been established that one of the main components of a planetary hydraulic motor, which causes pressure pulsations, is its distribution system. The frequency and amplitude of these pulsations depends on the kinematic diagram for the distribution system of the power fluid. Therefore, we studied how the kinematic diagram for the distribution system effects on the output characteristics of a planetary motor. Since the change in the capacity of a distribution system with various kinematic diagrams influences on the output characteristics of a planetary motor, the impact was investigated. The kinematic diagrams, which improve the output characteristics of planetary hydraulic motors, were justified. 

scholarly journals MATHEMATICAL MODEL OF THE INTERACTION OF THE SCREW WORKING BODIES OF FOREST FIRE GROUND-THROWING MACHINES WITH THE GROUND COVER

2021 ◽  
Vol 11 (1) ◽  
pp. 163-171
Author(s):  
Petr Popikov ◽  
Anton Pozdnyakov
Keyword(s):  
Mathematical Model ◽  
Forest Fire ◽  
Forest Fires ◽  
Hydraulic Drive ◽  
Ground Cover ◽  
Forest Litter ◽  
Working Fluid ◽  
Hydraulic Motor ◽  
Working Bodies ◽  
Fire Ground

The paper provides an overview of research on the working processes of screw working bodies of technological machines. It is noted that at present such important issues in the theory of auger working bodies as the required number of auger turns, the required position of the auger spiral in relation to the center, etc. have not been fully resolved, since the solution of these issues can provide an increased productivity of the tool. A structural and technological scheme of a forest fire machine with multifunctional modules is proposed, which consists of auger working bodies, which can be changed modularly with a screw metal thread for a brush, depending on the area and type of soil, the rotor of the thrower, with the ability to drive the cutters-throwers and auger working bodies both from the power take-off shaft of the tractor, and using a hydraulic motor, a guide casing. A mathematical model of an auger working body with a hydraulic drive has been compiled for removing the ground cover with forest litter when extinguishing forest fires with a ground gun, so that combustible materials do not fall into the fire zone together with the soil flow from the rotor-thrower. The working process of the hydraulic drive of the auger working bodies of a forest fire ground-sweeping machine is described by a system of differential equations, including the equations of translational and rotational movements of the auger working body and the equation of the flow rate of the working fluid. The problem of optimization of kinematic and dynamic parameters of auger working bodies of forest fire ground-sweeping machine is set

The Transitional Simulation of Self-Propelled Winch System by the AMESim

2014 ◽  
Vol 687-691 ◽  
pp. 228-231
Author(s):  
Jing Tao Yue ◽  
Hui Pu ◽  
Xiao Jun Wei
Keyword(s):  
Hydraulic System ◽  
Structural Characteristics ◽  
System Simulation ◽  
Hydraulic Drive ◽  
Simulation Models ◽  
Operating Conditions ◽  
The Self ◽  
Hydraulic Motor ◽  
Control Loops ◽  
System Operating

The self-propelled winch system was studied taking the 20-ton transitional self-driven winch system as the engineering background. By the analysis of structural characteristics, control loops, speed solutions and hydraulic motor-driven forms of winch hydraulic system, The system of mathematical models was established which lay the foundation of the establishment of system simulation model. The walking hydraulic drive system simulation models were established by using AMESim software. On this basis, by setting different parameters, the simulation system operating conditions are simulated, which verified the rationality and stability of the design of the winch hydraulic transmission system.

scholarly journals IMPROVEMENT OF TECHNOLOGICAL EQUIPMENT OF THE MACHINE FOR TRIMMING TREE CROWNS IN ROADSIDE FOREST BELTS

2017 ◽  
Vol 7 (1) ◽  
pp. 205-210
Author(s):  
Попиков ◽  
Petr Popikov ◽  
Бухтояров ◽  
Leonid Bukhtoyarov
Keyword(s):  
Hydraulic Drive ◽  
Hydraulic Cylinder ◽  
Operating Conditions ◽  
Cutting Process ◽  
Design Parameters ◽  
Working Fluid ◽  
Hydraulic Motor ◽  
Technological Parameters ◽  
Tree Crowns ◽  
Circular Saw

When cleaning cutting, pruning of branches of roadside trees and shelter belt contour cutters are widely used, cutters is designed for total horizontal, vertical and oblique trimming crowns. These devices are hinged or removable ones and aggregated with wheeled tractors of traction class 0.6 to 1.4 kN, widespread in forestry. Improving the design of such devices is made in the following areas: cutting devices and hydraulic drives. In the proposed working body of the machine for cutting tree crowns containing base machine, crane on the handle of which a rotary hydraulic motor (rotator)is mounted, the shaft of which has movable connection with the housing of the circular saw with one-sided sharpening in the direction of the detachable part of the branch, V-shaped emphasis in the form of unilateral action hydraulic cylinder with spring-loaded rod, piston cavity which is connected in series with the drain lines of the hydraulic motor which is mounted an adjustable throttle to create pressure of the working fluid (support). In this implementation of the device when circular goes deep into the branch, which is cut, the V - shaped support with spring-loaded rod moves all the way in the branch and eliminates the clamping of the saw blade in the cut, which will improve reliability and performance. The article has developed a mathematical model of device for pruning tree crowns by circular saw with hydraulic drive on the basis of common methodology for the simulation of planar mechanisms. Differential equations of the cutting process were composed. The model of proposed design of the device for cutting tree crowns allows to study the influence of geometrical and mechanical parameters of the branches of the trees, technological parameters of cutting process on energy consumption and quality of the cut, taking into account design parameters. The model allows also to assess the performance and to examine the effectiveness of the device in different operating conditions.

scholarly journals Establishment of rational parameters of temperature of working liquid in the hydraulic drive of the excavator of the fourth dimensional group at different equipment

2021 ◽  
pp. 98
Author(s):  
Igor Pimonov ◽  
Igor Pohorilyi ◽  
Maksim Fedyuchkov
Keyword(s):  
Hydraulic System ◽  
Hydraulic Drive ◽  
Internal Flow ◽  
Technical Condition ◽  
Working Fluid ◽  
Fluid Temperature ◽  
Hydraulic Motor ◽  
Dimensional Group ◽  
Increasing Temperature ◽  
Working Liquid

The article considers the hydraulic drive of a modern excavator on which the influence of the working fluid temperature on the power is established, depending on the technical condition of the hydraulic elements. Studies have shown that new pumps and which have operating wear, have different rational temperature of the working fluid. It is impossible to imagine modern construction machines without equipping them with a hydraulic drive. The operation of the hydraulic drive largely determines the efficiency of operation of both a single machine and the entire fleet, which consists of new and old machines . The efficiency of hydrated machines is ensured in their design, manufacture, and operation, where an important role is played by the parameters of the working fluid: the degree of its contamination and temperature (viscosity). The influence of the temperature of the working fluid on the efficiency of the hydraulic drive and the ability to control the efficiency of the hydraulic drive with the help of temperature have not been studied enough. One of the promising areas in determining the rational temperature of the working fluid is the development of new designs of heat exchangers, heaters, diagnostic devices, which will be able to assess the technical condition of individual elements and the hydraulic drive as a whole. Establishing a rational temperature of the working fluid as a necessary parameter of the hydraulic system is mandatory when using modern methods to increase the efficiency of operation, maintenance and repair of hydraulic drives. With increasing temperature of the working fluid, its viscosity decreases and the loss of pressure and power in the mains of the hydraulic drive. However, this increases the internal flow of hydraulic units, which leads to an increase in power loss. Studies have shown that new pumps and which have operational wear, have different rational temperature of the working fluid. At rational values of temperature to the hydraulic motor the worn out pumps can give almost twice more power, than at 50 ° C, recommended for new pumps. The driving power of the pump, thus, practically does not change.

scholarly journals DYNAMIC MODEL OF THE DRIVE MACHINES FOREST COMPLEX

2021 ◽  
Vol 4 (4) ◽  
pp. 102-108
Author(s):  
Roman Yudin ◽  
Rostislav Puzakov
Keyword(s):  
Mathematical Model ◽  
Dynamic Model ◽  
Hydraulic Drive ◽  
Process Dynamics ◽  
Dynamic Factors

The movement of the working body from the corresponding drive is described by a kinematic mathematical model that is adequate to the case of the absence of dynamic factors. This model should be adjusted and take into account the load dynamics. For the case of a mechanical drive of the working body, it is quite sufficient to determine the dependence of the process dynamics coefficient on a known combination of active factors. The working body is driven by a hydraulic drive, then when building a dynamic model of the object, it is necessary to take into account the hydrodynamics of the drive.

Energy Harvesting From Vertical Deflection of Railroad Track Using a Hydraulic System for Improving Railroad Track Safety

2011 ◽  
Author(s):  
Carl A. Nelson ◽  
Abolfazl Pourghodrat ◽  
Mahmood Fateh
Keyword(s):  
Rotational Motion ◽  
Hydraulic System ◽  
Hydraulic Cylinder ◽  
Hydraulic Pressure ◽  
Vertical Deflection ◽  
Hydraulic Motor ◽  
Railroad Track ◽  
Track Maintenance ◽  
Remote Areas ◽  
Railroad Crossings

Grade crossings are locations of significant interest for prevention of collisions, injuries and fatalities in the railroad transportation system. Another area of concern is track maintenance, since derailments resulting from mechanically deficient track structures can cause significant endangerment to property and lives. A commonality between these two classes of incidents is that many occur in remote areas due to the lack of electrical infrastructure to power automated warning systems and/or track health monitoring sensor networks. Providing electrical infrastructure to railroad crossings in remote areas is often not economical, and other alternative sources of electricity such as solar and wind energy are not reliable and robust. This motivated development of a hydraulic system capable of harnessing power from vertical deflection of railroad track due to passing railcar traffic. A hydraulic cylinder mounted under the bottom of the rail is compressed and relaxed by passage of each railcar, forcing the hydraulic fluid towards a hydraulic motor and converting the hydraulic pressure and flow into rotational motion and torque. The rotational motion is amplified to drive a PMDC generator. The hydraulic system was developed and testing was performed to verify the functionality of the hydraulic system and quantify the power output.

scholarly journals Hydraulic System with the Automatic Regulator of Liquid Flow and Investigation of its Operation

2018 ◽  
Vol 7 (4.7) ◽  
pp. 235
Author(s):  
Farit D. Bairamov ◽  
Bulat F. Bairamov
Keyword(s):  
Electric Motor ◽  
Hydraulic System ◽  
Rotation Frequency ◽  
Hydraulic Cylinder ◽  
Movement Speed ◽  
Hydraulic Motor ◽  
Hydraulic Actuators ◽  
Shaft Rotation ◽  
Automatic Regulator ◽  
Stability And Accuracy

Ensuring functioning of a hydraulic system requires the liquid consumption regulation given to the consumer. In hydraulic actuators by change of the liquid consumption regulation of the movement speed of an output link of the hydraulic engine is carried out: the movement speeds of the hydraulic cylinder piston or rotation frequency of a hydraulic motor shaft. In this work with the purpose of increase in efficiency of a hydraulic system and hydraulic actuators it is offered to use in them the most economical way of the liquid consumption regulation due to change of shaft rotation frequency of the pump engine. Schematic diagrams of a hydraulic system and hydraulic actuators with the automatic regulator of the liquid consumption are developed. For the drive of the pump the electric motor of alternating current is used. Shaft rotation frequency of the electric motor is regulated by the frequency converter.The linearized equations of dynamics of separate links of a hydraulic system from which after an exception of some variables the equations of dynamics of system in general are received are worked out. All equations are written down in a dimensionless form in relative deviations from a nominal operating mode of system. By consideration of hydraulic actuators the equation of dynamics of the hydraulic engine is in addition considered: hydraulic motor or hydraulic cylinder. At the same time the equations of dynamics of the pipeline and the hydraulic engine are replaced with one equation describing dynamics of the integrated link "the pipeline + the hydraulic engine".The research of stability and accuracy of functioning of a hydraulic system and hydraulic actuators is conducted. Accuracy of functioning is understood as the requirement that deviations of a consumption of the given liquid from its calculated value remained in in advance set limits. Stability conditions are received on the basis of Rauss - Gurvitz criterion, and for the solution of a problem of accuracy of functioning the method of functions of Lyapunov is used. The results received in article can be used at design of various adjustable hydraulic systems and hydraulic actuators for the rational choice of values of the parameters providing stability and accuracy of their functioning. 

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