ANALYSIS OF MECHANICAL POWER TRANSFORMATION PROCESSES DURING HARMONIC OSCILLATIONS OF DRIVES IN LOAD-LIFTING, TRANSPORTING AND VIBROFORMING CONCRETE MIXTURE MACHINES AND MECHANISMS

Abstract

The purpose of the study is to detail the types of mechanical power during harmonic oscillations of drives in load-lifting, transporting and vibroforming concrete mixture machines and mechanisms. Due to the irreversibility of thermal energy, its derivative will take only positive values. However, derivatives can be taken from both potential and kinetic energy. But the most interesting case is the case of harmonic os-cillations in the specified machines and mechanisms drives, for which the derivatives (instantaneous power) are sign-changing functions, that fundamently distinguishes them from thermal power. The analogue of kinetic energy in electric engineering is magnetic field energy in inductor coil, potential energy analogue is capacitor’s electric field energy, and mechanical thermal energy is replaced by thermal energy, which is dissipated by the resistor. It is shown in this study that not only thermal power (with a positive sign) develops during load-lifting, transporting and vibroforming concrete mixture machines and mechanisms drivers mechanical oscillations , but also sign-changing reactive powers, which characterize the kinetic and potential energies inverse. Here, the active power is understood as the average value of the instantaneous power for half a period, and under reactive − amplitude value. The full mechanic power of machines and mechanisms drives, on the one hand, is described by the Pythagorean formula, and from the other − is equal to the product of the harmonic quantities effec-tive values. A feature of the complex representation is that when calculating the full power, one of the vectors that are multiplied must be conjugate. The representation about mechanical reactive, active and full power is a generalization of the corre-sponding consepts from electrical engineering, which is a manifestation of electro-mechanical dualism. Since in most machines and mechanisms the drives are mainly electromechanical, mechanical reactive power transforms into electrical reactive power of the network, thereby worsening the quality of electricity. Therefore, con-sideration of mechanical reactive power is of great importance.