Design of measuring bench to measure the operating frequency of rotating shafts

Abstract

One of the important characteristics of rotating shafts and machine components during operation is the critical speed, which is related to the operating frequency of the rotating assembly. In reality, the shaft is a flexible element which, when an unbalanced rotor is mounted, is subjected to a centrifugal force proportional to the square of the angular velocity and the eccentricity. The excitatory effects associated with this can lead to harmful vibrations. At the critical speed, the rotor behaves restlessly, the amplitude of the machine's vibrations increases. When designing, it must be ensured that the machine cannot operate permanently at the critical speed. There are mechanical models for determining the critical speed of such systems, but a more accurate picture can be obtained by measuring the resonance occurring during rotation of the real shaft. The article summarizes the results of measurements carried out on such a measuring bench.