Vibration Analysis of Rotor Bearing Housings Considering Unbalancing in Two Planes

Abstract

Unbalancing and misalignment are the most possible causes of machine vibrations. An unbalanced rotor always causes more vibration and generates excessive force in the bearing area and reduces the life of the machine. Understanding and practicing the fundamentals of rotating shaft parameters is the first step in reducing unnecessary vibration, reducing maintenance costs and increasing machine uptime. By the term two planes here, we mean that two rotors are used for the analysis of unbalanced vibrations. If only one rotor is used, then this system is called a single-plane system. In this paper, experimental studies were performed on a 2 rotor dynamic test apparatus to predict the vibration spectrum for rotor unbalance. Two rotor bearings were used in the experiments. The rotor shaft velocities were measured at rotor speed of 30 Hz using an accelerometer and a dual channel vibration analyzer (DCVA) under the balanced (baseline) and unbalanced conditions. The experimental frequency spectrum was also obtained for both baseline and unbalanced condition under different unbalanced forces. The experimental results of balanced and unbalanced rotors are compared at two different rotor locations.