STUDY OF DYNAMIC PROCESSES, ARISING UP IN KNOTS OF SCISSORS DRIVE WITH PARALLEL KNIVES

Abstract

Full clarity in the processes that accompany the work of mechanisms that are in difficult dynamic conditions allows the designer to choose the right solution that ensures the normal operation of the machine. Of particular importance is the dynamics of mechanisms in the calculations and design of heavy metallurgical and mining equipment, as well as heavy construction machines, when it is impossible to make research samples in most cases. Studies in the field of dynamic calculations of mechanical systems revealed that quite significant additional loads in real machines arise at the moments of their operation in transitional modes, that is, during the transition of a system from one stable position to another. An important and necessary stage in the design of new mechanical systems is the study of the free oscillations of the system within their stable equilibrium. During transients, the load mechanisms acting in the transmission line, as a rule, significantly differ from static and inertial loads due to their magnitude and nature of variability. This is due to the elastic vibrations of the systems, which often accompany the operation of many mechanisms and machines under dynamic load. Studies of the dynamic processes arising in the nodes of the drive scissors with parallel knives indicate that during cutting, there are so-called transients that have an effect on the occurrence of additional dynamic loads. These loads are somewhat different from static and inertial in their size and nature of variability, which is explained by their oscillatory nature. The compiled above calculation scheme of free vibrations of scissors with parallel knives arising in the drive made it possible to obtain a system of equations, their general solution allows to calculate the amplitude and period of free vibrations arising in the scissors drive during the cutting process. The initial data for these calculations we found to be the moments of inertia of the scissors and the counterweight drive, as well as the reduced stiffness of the rod of the spring balancing system. The reduced scheme for calculating tаааhe free oscillations of the scissors in the drive is compiled and a system of equations that allows calculating the amplitude and period of free oscillations, with known mome