scholarly journals INVESTIGATION OF TRANSITIONAL PROCESSES IN THE ADAPTIVE SYSTEM OF HYDRAULIC DRIVES OF THE MECHANISM FOR CUTTING AND UNLOADING STALK FODDER

2021 ◽  
pp. 107-114 ◽  
Author(s):  
Volodymyr Rutkevych
Keyword(s):  
Adaptive Systems ◽  
Adaptive System ◽  
Hydraulic Drive ◽  
Hydraulic Cylinder ◽  
Slide Valve ◽  
Drive System ◽  
Design Parameters ◽  
Flow Divider ◽  
Competitive Mechanism ◽  
Transitional Processes

The problem of creating an energy-efficient and competitive mechanism for cutting and unloading stalk fodder from trench storage, by developing and justifying the parameters and modes of operation of the adaptive system of hydraulic drives of the mechanism is researched. The principal implementation of the adaptive system of hydraulic drive of the mechanism for cutting and unloading is proposed, in which a spool flow divider is placed between two executive hydraulic motors, which allows to regulate the supply of a U–shaped frame according to the load change which affects the cutting mechanism. The adaptive system of the hydraulic drive of the mechanism allows to stabilize energy consumption for separation of a portion of a stalk fodder under the condition of change and fluctuation of parameters which essentially influence the process of separation and unloading of a stalk fodder from the monolith. The transients in the adaptive systems of hydraulic drives of the mechanism for cutting and unloading of stalk fodder are received and analyzed. As a result of the study, it was found that by changing the operating widths of the slide valve of the separator in the direction of reduction, a significant increase in the responsiveness of the hydraulic drive system of the mechanism for cutting and unloading to the changes in the loading on the cutting apparatus. As a result, the range of the adjustment of the feeding of the hydraulic cylinder of the U–shaped frame, which increases the efficiency of stabilizing the separation process from the monolith of block-portion of stalk fodder with a minimum power of the hydraulic drive system, is substantially expanded. It is noted that the dynamic characteristics of the hydraulic drive of the mechanism for cutting and unloading stalk fodder adaptive to the load are influenced by the design parameters of the spool flow divider which implements feedback. On the basis of the conducted experimental research recommendations on the choice of constructive parameters of the spool flow divider are given.

Analysis of Flow Resistance Influence on Step-Down Process of the Control Rod Hydraulic Drive System

2021 ◽  
Author(s):  
Linqing Yang ◽  
Benke Qin ◽  
Hanliang Bo
Keyword(s):  
Theoretical Model ◽  
Flow Resistance ◽  
Inflection Point ◽  
Great Influence ◽  
Hydraulic Drive ◽  
Hydraulic Cylinder ◽  
Drive System ◽  
Pressure Curve ◽  
Control Rod ◽  
Step Down

Abstract Control rod hydraulic drive system (CRHDS) is a new type of built-in control rod drive technology which is invented by INET, Tsinghua University. The integrated valve (IV) is the main flow control component of the CRHDS. Flow resistance of IV has a great influence on the control rod dynamic step-down process. The step-down performance experiments of CRHDS with different flow resistance of IV were conducted under room temperature conditions. Meanwhile, the theoretical model of hydraulic cylinder step-down process was established and combined with the relationship of the flow resistance of IV under the experimental conditions to get the dynamic response of the hydraulic cylinder. The calculation results of theoretical model agree well with the experimental data. On this basis, the theoretical model of hydraulic cylinder step-down process was applied to the high temperature working conditions with different flow resistance of IV. The analysis results show that at higher working temperature, with the increase of the flow resistance of IV control rod step-down average velocity decreases and step-down time increases correspondingly. There is an inflection point in the transient pressure curve and the pressure of the inflection point decreases gradually with the increase of the flow resistance. The pressure lag time after step-down also decreases. The research results lay the base for the design and optimization of the flow resistance of the IV for the CRHDS.

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 Simulation of the hydraulic system of a device with self-adaptation for power and kinematic parameters on the working body

2021 ◽  
Vol 21 (1) ◽  
pp. 55-61
Author(s):  
T. A. Khinikadze ◽  
A. T. Rybak ◽  
P. I. Popikov
Keyword(s):  
Mathematical Model ◽  
Hydraulic System ◽  
Adaptive Systems ◽  
Dynamic Properties ◽  
Hydraulic Drive ◽  
Operating Conditions ◽  
Design Parameters ◽  
Rock Drilling ◽  
Self Adaptation ◽  
The Mathematical Model

Introduction. Currently, Russia has adopted a course towards the creation of intelligent machines and equipment. The same holds for mobile technological machines for road construction and public utilities. Therefore, the design and creation of this type of actuators with a self-adaptation function is a critical task.Materials and Methods. A device equipped with a hydraulic drive with self-adaptation to load and coordination of kinematic and power parameters of the principal motion and the feed movement of the working body of the rock- drilling rig, is presented. To study and design the device based on the mathematical modeling methods of a hydraulic drive and adaptive systems, a mathematical model is proposed. It is developed using the foundations of the theory of volumetric stiffness of hydraulic systems. This enables to accurately describe the impact of the dynamic properties of the hydraulic system (compressibility of the working fluid, elastic properties of pipelines, high-pressure  hoses, hydraulic apparatuses) on the dynamic properties of the system as a whole.Results. The mathematical model for a device with self-adaptation includes submodels of adaptive communication, interrelations of power, kinematic and process parameters of rock drilling, as well as mathematical description of the movement of system elements. The solution to the developed mathematical model was performed in the software environment for dynamic modeling of technical systems SimInTech. As a result, general dependences of the adaptive system on the design parameters of the system and the operating conditions are obtained.Discussion and Conclusion. The mathematical model of the presented device shows the fundamental possibility of implementing the principle of self-adaptation in terms of load under external and internal disturbing actions during operation. The results obtained can be used under designing adaptive systems of other technological equipment, for example, for the implementation of deep drilling in workpieces with variable properties in its depth.

Impact Assessment of Dynamic Characteristics on the Hydraulic Driven Machinery Operation

2018 ◽  
pp. 1-12
Author(s):  
A. D. Terenteva
Keyword(s):  
Dynamic Error ◽  
Total Error ◽  
Soil Layer ◽  
Hydraulic Drive ◽  
Hydraulic Cylinder ◽  
Working Mechanism ◽  
Automated Control ◽  
Vertical Coordinate ◽  
Construction Machinery ◽  
The Difference

In civil engineering in Russia, trenching for utilities is currently under digging. To perform such works, it is necessary to use high-precision construction machinery, because inaccurate performance of works can lead to the break down of existing utilities, thereby affecting the residents of nearby houses and demanding the additional works for renewal.The most universal labour saver to perform construction works is hydraulic driven single-bucket excavators, which provide up to 38% of works. Therefore, to improve technical characteristics that affect the accuracy of the work performed is an important task.High requirements for the performance of works are defined by existing construction regulations: an allowable soil layer to remain is at most 0.05 m. To fulfil such requirements, an exact assessment of the working mechanism position and a trench profile is necessary.Examination of a manually operated digging process shows that an operator provides operations untimely, however an automated control system can solve this problem. Dynamic phenomena in the working mechanism have the greatest impact on the accuracy of the works performed.To assess the bucket digging edge position accuracy, a mathematical model of the working mechanism has been created. Based on the cycle scheme of the working process, the excessive displacements of the hydraulic cylinder rods under the load are taken into account. By the end of the cycle, the difference between the specified and obtained positions along the vertical coordinate has been 0.0892 m.A dynamic error of the hydraulic drive system of the working mechanism is considered as a sum of the error due to excessive displacements of the hydraulic cylinder rods and the error due to delay of the hydraulic drive, with the latter being calculated for the average time of delay taking into account the data available in the literature. The total error of the bucket digging edge position of the working mechanism is 0.1176 m, which is 2 times more than the value of 0.05 mConformity of all the links with specification requirements does not guarantee compliance with the required displacement accuracy of the bucket digging edge, and, thus, the soil layer to remain in the base of the trench can exceed the regulated value of 0.05 m.

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.

Development of hydraulic cylinder diagnostic methods by modeling methods

2021 ◽  
pp. 41-45
Author(s):  
Keyword(s):  
Hydraulic Drive ◽  
Hydraulic Cylinder ◽  
Technical Condition ◽  
Diagnostic Methods ◽  
Technical Diagnostics ◽  
Remaining Service Life ◽  
Construction Machine ◽  
Piston Speed ◽  
Variable Nature ◽  
Hydraulic Cylinders

The hydraulic drive of a construction machine is a complex dynamic system that is subjected to many dynamic loads of a variable nature and operates under conditions of variable external influences caused by various factors. During operation, these loads cause failure of the hydraulic transmission elements. To prevent these malfunctions, technical diagnostics should be applied by determining their current technical condition and remaining service life. The article assesses the working condition of hydraulic cylinders using a mathematical model. Using matlab/simulink software to simulate the hydraulic cylinder and hydraulic piston speed when changing the hydraulic cylinder clearance. The simulation results are presented. Keywords: diagnostic, hydraulic cylinder, simulation, development

Sign in / Sign up

Export Citation Format

Share Document