scholarly journals VIBRATION PROCESSES MODELING IN A PERISTALTIC CONCRETE PUMP WITH HYDRAULIC DRIVE

Author(s):  
Vladimir Shatokhin ◽  
Boris Granko ◽  
Vladimir Sobol

The research results of the mathematical model development of dynamic processes in a peristaltic concrete pump with a hydraulic drive are presented. Cast concrete occupies a leading place in modern construction. Peristaltic concrete pumps are good proved in this area. Developing of devices for performance of such activities is an actual task. One of contemporary efficient directions in its solving is an adequate modeling of dynamic processes in mentioned devices. The model is development in the form of a differential equation for rotation angle of the pump rotor; contains general geometric characteristics, rotor’s mass characteristics, dynamic characteristics of the hydraulic motor, parameters of the hose and a structural mix. A method has been developed for the resistance torque forming to rotation of the pump rotor from rollers deforming the hose. A model of the friction forces during the movement of the structural mix is proposed. An expression is obtained for the resistance forces as result of gravity forces action on the mix particles in the outlet part of the hose. An approach is proposed for using catalog data to represent the torque of a hydraulic motor as a function of the angular velocity of its rotor. Researches of dynamic processes by using the proposed model are carried out. Important technological regularities of the unit functioning have been established, in particular: the mortar speed may have a significant variable component; the mortar speed and the pump performance increase with a decrease in the length of the outlet hose and a decrease in its height, a decrease in the rolling friction coefficients for the rollers, and not using of the side rollers. The conducted research show that an increase of an altitude leads to a decrease in the average speed of the mixture and the frequency of pulsations. In this case the amplitude of velocity pulsations increases. With an increase in the length of a deferent hose, the amplitude of velocity pulsations changes insignificantly. The rejection of side rollers leads to an increase in the average speed of the mixture motion with minor pulsations. The walls of the hose, however, in this case experience more intense bending stresses, which reduce the product life of the hose.

2020 ◽  
Vol 26 (3) ◽  
pp. 126-130
Author(s):  
Krasimir Kalev

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.


2020 ◽  
pp. 77-78

The use of ultra-high molecular weight polyethylene (UHMW PE) for the manufacture of various parts, in particular cuffs for hydraulic drives, is proposed. The properties and advantages of UHMW PE in comparison with other polyethylene materials are considered. Keywords ultra-high molecular weight polyethylene, hydraulic pump, hydraulic motor, hydraulic control valve, hydraulic oil, low temperature. [email protected]


2019 ◽  
Vol 19 (3) ◽  
pp. 242-249 ◽  
Author(s):  
A. T. Rybak ◽  
I. K. Tsybriy ◽  
S. V. Nosachev ◽  
A. R. Zenin

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.


Author(s):  
Prabhakar Kushwaha ◽  
Sanjoy K Ghoshal ◽  
Kabir Dasgupta

A flywheel is presented in this article, which can adaptively generate variable inertia in response to the application requirements in a hydraulic drive. The said flywheel consists of four sliders in the guide track of a host flywheel frame which change its position as the rotational speed of the flywheel varies. The varying distance between the slider and the center of rotation leads to a variable inertial mass. This passive inertial mass has a potential to reduce the speed fluctuations of the drive. A comparative study has been made on the effects of the variable inertia flywheel on the hydraulic motor speed fluctuations with that of the fixed inertia flywheel. In this respect, a bond graph model of the hydraulic motor drive with the variable inertia flywheel and the fixed inertia flywheel is developed to analyze their performances. The variable inertia generated by the variable inertia flywheel reduces the hydraulic motor speed fluctuations in response to the changes in the excitation inputs. The tests were conducted to validate the model for step change in speed of the hydraulic motor. The test results of the hydraulic motor speed response are found in good agreement with the predicted response. The proposed design of the flywheel reduces the peak speed of the hydraulic motor that enhances the reliability and performance of the drive.


2018 ◽  
Vol 7 (4.3) ◽  
pp. 6 ◽  
Author(s):  
Angela Voloshina ◽  
Anatolii Panchenko ◽  
Oleg Boltynskiy ◽  
Igor Panchenko ◽  
Olena Titova

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. 


2021 ◽  
Vol 11 (1) ◽  
pp. 163-171
Author(s):  
Petr Popikov ◽  
Anton Pozdnyakov

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


2014 ◽  
Vol 687-691 ◽  
pp. 228-231
Author(s):  
Jing Tao Yue ◽  
Hui Pu ◽  
Xiao Jun Wei

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.


2021 ◽  
Vol 1 (142) ◽  
pp. 72-82
Author(s):  
Sergey Pyanzov ◽  
◽  
Pavel Ionov ◽  
Aleksandr Zemskov ◽  
Aleksey Stolyarov

Currently, manufacturers for a reliable assessment of the technical condition of volumetric hydraulic drives use the dynamic test method, which allows you to determine the torque (braking) moment on the shaft of the tested hydraulic motor. There are diffi culties in reliably determining the value of the developed torque (braking) moment. (Research purpose) The research purpose is in constructing a mathematical model of the relationship between the developed torque (braking) moment of a volumetric hydraulic drive and the parameters of a hydraulic loading device. (Materials and methods) The article presents a hydraulic loading device that provides the necessary braking torque on the shaft of the tested hydraulic motor. Authors conducted one-factor and multifactor experiments-dynamic tests of the new Sauer-Danfoss series 90 volumetric hydraulic drive using a hydraulic loading device. The torque (braking) was monitored using a non-contact digital torque sensor M 425 3-A datum electronics and a digital indicator with LCD display (Results and discussion) As a result of one-factor passive experiments, the factors infl uencing the optimization parameter and the ranges of their variation were determined. A mathematical model of the relationship between the developed torque (braking) moment of a volumetric hydraulic drive and the parameters of a hydraulic loading device was obtained by a multi-factor active experiment. The article presents a complete planning matrix for a multi-factor active experiment, which refl ects the sequence of all possible combinations of factors that affect the optimization parameter. The most signifi cant factors affecting the value of the developed torque (braking) moment were: the pressure drop and the temperature of the working fluid in the hydraulic lines of the hydraulic loading device. (Conclusions) The mathematical model allows us to determine with high accuracy the developed torque (braking) of the volumetric hydraulic drive.


2019 ◽  
Vol 2019 ◽  
pp. 1-17
Author(s):  
Ngoc Hai Tran ◽  
Cung Le ◽  
Anh Dung Ngo

In this article, we present an experimental study on the speed stability of a spindle driven by a hydraulic motor, which is controlled by a proportional valve, through a V-belt transmission. The research includes the dynamic modeling of the transmission cluster and the transmission from the hydraulic motor to the working shaft via V-belt mechanism, together with the establishment of a mathematical model and fuzzy self-tuning PID controller model. In the model, the V-belt is assumed as an elastic module, and the friction coefficient and mass inertia moment of the hydraulic motor are considered as constant. The Matlab software is used to simulate the speed response of the hydraulic motor to the working shaft. Based on theoretical study, we resemble the experimental system and determine the parameters for the fuzzy self-tuning PID controller. We conduct experiment and investigate the speed stability of the working shaft from 300 to 1100 (rpm) based on transient response parameters such as the time delay, the setting time, the overshoot, and the rotation error at steady state. Thereby, in this study, the simulation and the experiment results are compared and evaluated regarding the speed stability of the working shaft driven by hydraulic motor transmitted through V-belt mechanism. The findings show the speed controllability by using proportional valve to manipulate the oil flow and applying a self-tuning PID controller to achieve very good results such as the error difference of 0.001 to 0.036%, the delay of 0.01 to 0.02 seconds, no overshoot, and the settling error less than 5% compared to the set values. On the other hand, we include the effect of the oil temperature of 40 to 80°C on the working shaft speed (500, 900 rpm) in this study and derive that the system works well at temperature range of 40 to 70°C. On these findings, we propose the applicability of this system on the current machinery cutters. In addition, we verify the effects of the hydraulic drive for main shaft, controlled by fuzzy PID, by comparison of the roughness of the machining work piece with respect to the one using the 3-phase motor drive.


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