Vytautas Barzdaitis

Dynamics of a mechatronic system with flexible vertical rotor

The paper is dedicated to research on flexible rotor systems with anisotropic rotor material properties. In addition, the anisotropy of rotor supports alters the rotor system resonance frequencies and the machine has to pass till it attains the operating angular speed. This phenomenon of rotor vibration is observed in vertical rotors. The aim of this work is to compare experimental vibration measurements and results of theoretical modeling. In the paper theoretical model, created from physical one of really existing rotor system is described. Collected experimental data of rotor vibrations in bearings are compared with results of theoretically derived equations. The results of theoretical modeling and research enables for estimation of a more precise technical condition of the rotor system both after the overhaul and during the maintenance and thus to avoid unexpected breakdowns, especially concerning the fatigue development in ball bearing elements.

Dynamic Processes of Rotating System with Coupling

The article concerns dynamics and vibration of a high power rotating system with toothed wheel coupling that inserts elastic plate packets. Theoretical modeling and simulation of the rotating system with toothed wheel coupling have been provided by a finite element method. Complex model involved a rotating system, hydrodynamic bearings and coupling. The dynamics of semi-couplings and plates have been simulated. Experimental measurement of vibration has been measured with stationary machine condition monitoring and a diagnostic system.

Diagnostics Problems and Decisions of Low Rotation Speed Rotors with Antifriction Bearings

The essence of the paper was to design technical condition monitoring and failure diagnostic evaluation method of low rotation speed rotors with self-aligning antifriction roller bearings. The technical condition of bearings and failures of the cylindrical rollers and cylindrical wheels surfaces were tested in situ using mechanical vibration parameters measurement method. The theoretical part of the paper was constrained to the modeling of two cylinders in the case of different damages levels of the spherical roller bearings.

Modeling and Diagnostics of Heavy Impeller Gyroscopic Rotor with Tilting Pad Journal Bearings

The work presents the study of dynamics of heavy impeller rotor and failure diagnostics of tilting-pad journal bearings. The started rubbing process in the bearings at resonance and increased rubbing phenomenon in both bearings by measurement of radial gaps, were identified experimentally in situ. The rotational speed was established when gravitational force became dominant compared to rotor gyroscopic force. Rotating system model was designed, simulated and verified.

Diagnostics Modeling of Vertical Rotor Vibration

This paper deals with condition monitoring and vibration diagnostics of vertical sulphuric acid pumps running in continuous long term operation mode. The task of experimental testing and theoretical modeling – to increase reliability and efficiency of vertical pumps through elimination of rotor lateral vibration. On the basis of experimental testing results analysis the dynamic model was designed and simulated. The reason of high vibration of the pump rotor is the rotor technological bow and cavitation phenomenon that take place in the pump.