VIBROGEN - An experimental system to study vibration waveforms generated by faults under arbitrary load conditions

Abstract

An electronic experimental system is built in order to generate and record mechanical vibrations in controlled conditions, loads and faults. Mechanical faults are considered and introduced by bearings fixed on rotating shaft. A universal electric motor spins the shaft at known and imposed angular speed, acceleration sensors are used to measure the vibration, and the useful signals are introduced in Matlab/Simulink workspace via data acquisition toolbox and high speed acquisition board. Aim is to determine typical patterns of vibrations caused by mechanical faults and critical loads. The faulty element could be a ball in the bearing, a broken ring, or a misaligned shaft/bearing/load. A gearbox between the sensors and the faulty element is considered to study the spectrum translation of the vibration, according to the speed ratio of the gearbox. A controlled load, consisting in a DC motor and a power MOS-FET across its terminals is used to induce step variations in the load of the main motor/shaft.