On stability of the dual-frequency motion modes of a single-mass vibratory machine with a vibration exciter in the form of a passive auto-balancer
Journal Title: Восточно-Европейский журнал передовых технологий - Year 2018, Vol 2, Issue 7
Abstract
<p>By employing computational experiments, we investigated stability of the dual-frequency modes of motion of a single-mass vibratory machine with translational rectilinear motion of the platform and a vibration exciter in the form of a passive auto-balancer.</p><p>For the vibratory machines that are actually applied, the forces of external and internal resistance are small, with the mass of loads much less than the mass of the platform. Under these conditions, there are three characteristic rotor speeds. In this case, at the rotor speeds:</p><p>– lower than the first characteristic speed, there is only one possible frequency at which loads get stuck; it is a pre-resonance frequency;</p><p>– positioned between the first and second characteristic speeds, there are three possible frequencies at which loads get stuck, among which only one is a pre-resonant frequency;</p><p>– positioned between the second and third characteristic speeds, there are three possible frequencies at which loads get stuck; all of them are the over-resonant frequencies;</p><p>– exceeding the third characteristic speed, there is only one possible frequency at which loads get stuck; it is the over-resonant frequency and it is close to the rotor speed.</p><p>Under a stable dual-frequency motion mode, the loads: create the greatest imbalance; rotate synchronously as a whole, at a pre-resonant frequency. The auto-balancer excites almost perfect dual-frequency vibrations. Deviations of the precise solution (derived by integration) from the approximated solution (established previously using the method of the small parameter) are equivalent to the ratio of the mass of loads to the mass of the entire machine. That is why, for actual machines, deviations do not exceed 2 %.</p><p>There is the critical speed above which a dual-frequency motion mode loses stability. This speed is less than the second characteristic speed and greatly depends on all dimensionless parameters of the system.</p><p>At a decrease in the ratio of the mass of balls to the mass of the entire system, critical speed tends to the second characteristic speed. However, this characteristic speed cannot be used for the approximate computation of critical speed due to an error, rapidly increasing at an increase in the ratio of the mass of balls to the mass of the system. Based on the results of a computational experiment, we have derived a function of dimensionless parameters, which makes it possible to approximately calculate the critical speed.</p>
Authors and Affiliations
Volodymyr Yatsun, Gennadiy Filimonikhin, Antonina Haleeva, Andrey Nevdakha
Construction of methods for determining the contours of objects on tonal aerospace images based on the ant algorithms
<p>A method has been proposed for determining contours of objects on tonal aerospace images based on ant algorithms. The method, in contrast to those already known, takes into consideration patterns in the image formatio...
Plasmochemical preparation of silver nanoparticles: thermodynamics and kinetics analysis of the process
<p>The thermodynamics and kinetics analysis of the plasmochemical formation of silver nanoparticles is performed. The thermodynamics analysis is made on the basis of calculation of the Gibbs free energy of formation of s...
The study of properties of composite adsorptive materials “silica gel – crystalline hydrate” for heat storage devices
<p>Heat energy storage is one of the most common technical solutions in the conditions of operation of low-potential and renewable energy sources. Adsorption heat energy storage devices based on the composite media “sili...
Analysis of the developed quantitative method for automatic attribution of scientific and technical text content written in Ukrainian
<p>A formal approach was proposed to implement text content attribution. The study was conducted with Ukrainian scientific and technical texts. The results of application of the designed algorithms of automatic attributi...
Identification of energy efficiency of ore grinding and the liner wear by a threephase motion of balls in a mill
<p>We have analytically derived an equation that relates the technological parameters of a ball mill, grinding material, to the parameters of a rod primary converter of energy efficiency of ore grinding. By using a metho...