Estimation of the resonance amplitude in machines with inertia vibrator in the coast-down phase

The work concerns mechanical systems with transient resonance formed as a result of an unbalanced rotating mass passing through an area of the system's natural frequency. In particular, this concerns over-resonant vibrating machines driven by inertia vibrators, which during start-up and coast-down pass through the natural frequency area related to the vibrating mass – flexible suspension system. The work analyses a system consisting of a soft-mounted machine body excited into vibrations by means of the inertia vibrator in order to designate the amplitude of resonant vibration, taking into consideration strong coupling between movements of the body and vibrator. The research results are presented in the form of nomograms and approximation formulas expressed in terms of relative parameters. The results of the theoretical research were verified on the laboratory model and industrial machines.

Feed Material Influence on the Dynamics of the Suspended Screen at Its Steady State Operation and Transient States

The influence of the feed material on steady vibrations as well as on the transient resonance during the start-up and coasting of the suspended screen, was analysed in the hereby paper. The influence of the feed material presence on the possibility of performing the first half-turn of the vibrator was also established. The original, feed material simulation model reflecting its layer properties and diversification of feed particles vibrations along the screen riddle – specially developed for this aim – was applied in investigations.

Maximal Amplitudes of Vibrations of the Suspended Screens, During the Transient Resonance

A usefulness of known methods for estimations of maximal amplitudes of suspended vibrating screens, in the transient resonance, was analysed in the paper. The way of adapting – for this type of machines – the new, developed by the authors, methods of analysing the transient resonance was indicated. Their accuracy was estimated by comparing the obtained results with the results of simulation investigations performed on the model, which takes into account the influence of the body vibrations on the vibrator motion.