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.Keywords: vibrating screens, systems of limited excitations, transient resonance W pracy poddano analizie przydatność znanych metod dla oceny maksymalnych amplitud w rezonansie przejściowym przesiewaczy typu podwieszonego. W szczególności wskazano sposób zaadaptowania dla tego typu maszyn nowych, opracowanych przez autorów, metod analizy rezonansu przejściowego i oceniono ich dokładność przez porównanie z badaniami symulacyjnymi wykonanymi na modelu uwzględniającym zwrotne oddziaływanie drgań korpusu na ruch wibratora.Słowa kluczowe: przesiewacze wibracyjne, układy o ograniczonym wzbudzeniu, rezonans przejściowy

The solution of a system exciting wire vibrations of a wire sensor allowing one to perform time-varying measurements, including rapid changes and of a chaotic nature, are presented in this paper. The system is based on the typical two-coil solution, in which one of the coils is responsible for exciting the wire vibrations while the other coil is used for recording those vibrations. The task of maintaining and not fading away the natural vibrations of the wire was solved by the excitation of self-exciting vibrations by the impulse system synchronized using the wire motion velocity. The mathematical analysis of the wire motion in the system with the impulse generator, in which the existence of the limiting cycle of the wire natural frequency was proved, is shown in this paper. The computer simulation results, illustrating the metrological possibilities of the solution as well as an example of a physical implementation, are also presented.

The paper concerns the analysis of a self-synchronization process of inertial vibrators in general motion. These types of systems are found e.g. in the case of vibratory conveyors, in which the synchronization plane of vibrators is perpendicular to the plane of vibration of the conveyor trough. The analysis is focused on two basic issues related to movement of the vibrator. The first issue concerns conditions for obtaining stable motion in a configuration ensuring generation of useful vibrations. The second one is determination of the value of the synchronizing moment. In order to obtain analytical dependencies as simply as possible, we considered a typical build conveyor and the suspension, whose mathematical description we can bring to a diagonal form.In the paper, we paid attention to the consequences of using suspensions with highly directional properties, e.g. metal-elastomer vibration isolators.

DISTURBANCES IN SELF-SYNCHRONISATION OF VIBRATORS IN VIBRATORY MACHINES ZABURZENIA SAMOSYNCHRONIZACJI WIBRATORÓW W MASZYNACH WIBRACYJNYCHAn influence of elastic support elements arrangements and ratios of elasticity and damping constants in vertical and horizontal direction on self-synchronisation accuracy was investigated in the paper. The obtained results of the other factors influence on disturbances in self-synchronisation of vibrators in vibratory machines are also presented. Especially, influence of a diversification of driving and anti-torque moments, not central direction of the resulting force of the vibrators set , the local flexibility of mounting of vibrators to the machine body and influence of collisions with a feed were described. Keywords: vibratory machines, self-synchronisation, phase incompatibility of vibrators motion W pracy zbadano wpływ rozmieszczenia elementów sprężystych zawieszenia i proporcji pomiędzy stałymi sprężystości i tłumienia tych elementów na kierunkach pionowym i poziomym na dokładność samosynchronizacji wibratorów. Przytoczono też rezultaty badań autorów nad wpływem innych przyczyn na zaburzenia samosynchronizacji wibratorów maszyn wibracyjnych. W szczególności określono wpływ na zjawisko samosynchronizacji takich zjawisk jak: zróżnicowanie momentów napędowych i oporowych, niecentralne ukierunkowanie wypadkowej siły wymuszającej zespołu wibratorów, lokalna podatność zamocowania wibratorów do korpusu maszyny i oddziaływanie zderzeń z nadawą.Słowa kluczowe: maszyny wibracyjne, samosynchronizacja, niewspółfazowość ruchu wibratorów

The work concerns wire transducers, which use a system with a van der Pol oscillator with the aim of maintaining nondecreasing natural vibrations in the wire. As opposed to classical solutions, in which the feedback signal of the oscillator contains the course of displacement and velocity of the vibrating mass, a simple solution based only on the course of velocity is used. Such a solution is more advantageous from a practical perspective as regards to physical systems because, in the case of velocity transducers, it eliminates the need to integrate the signal and the problems connected with it.Particular places for this solution may be found in wire tensometer systems designated for the long-term constant measurement, as well as for the measurement of time-variable courses, including those of a chaotic character.In the work, analysis was conducted on a modified van der Pol equation adapted for the movement of a discrete mass for the determination conditions of the existence of a limit cycle, the vibration course, as well as the definition of the capabilities of adapting the results in the case of a wire transducer.The results of theoretical analysis were confirmed by the results of the experimental tests conducted on a laboratory model constructed for this purpose.