Dynamic processes modeling in a peristaltic concrete pump with a hydraulic drive

Abstract

Problem. 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. Currently efforts of researches are focused on resolving of separate tasks connected with developing of new models of peristaltic pumps.Goal. The creation of a universal mathematical model for dynamic processes in a peristaltic concrete pump with hydraulic drive to determine the technological device qualities and the choice of its rational parameters. The model should contain the basic geometric, mass characteristics of the rotor, the dynamic characteristic of a hydraulic motor, the parameters of the hose and building mixture. The following tasks are solved: development of the method for generating a moment of resistance on a pump rotor from rollers, that deforms a hose; creation of a model for friction forces, which prevent the movement of the building mixture; obtaining an expression for resistance forces, which exist due to the gravity forces of the mixture particles in the deferent part of the hose; building of the model of the torque for the hydraulic motor as a function of the angular velocity of its rotor using catalog data. Methodology. For the research of rotation dynamic processes it is proposed the usage of differential equation of motion written in the Lagrange form. The angle of rotation of the pump rotor is taken as a generalized coordinate. Results. The mathematical model of dynamic processes in a peristaltic concrete pump with hydraulic motor are created in the form of a differential equation for the angle of rotation of the rotor. The method for generating of the resistance moment to the rotation of the pump rotor from rollers, that deform the hose, is developed. The model for resistance forces to the movement of a building mixture is proposed. The expression for resistance forces, which exists due to the gravity forces of the mixture particles in the deferent part of the hose, is obtained. The approach for usage of catalog data to represent the torque of a hydraulic motor as a function of the angular velocity of its rotor is proposed. Originality. Important technological regularities of the device functioning were established: the speed of the mixture motion can have a significant variable component; the speed of the mixture motion and pump’s performance increase with a decrease in the length of the discharge hose and a decrease in its height, a decrease in the rolling friction coefficients for the rollers and a rejection of side rollers. Practical value. 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.