Rotor unbalance and shaft misalignment are major concerns in rotating machinery. In order to understand the dynamic characteristics of these machinery faults a model of complete motor flexible coupling rotor system capable of describing these failures was developed. Unbalance is the most cause of machine vibration, an unbalanced rotor always cause more vibration and generates excessive force in the bearing area and reduces the life of the machine. Experimental studies were performed on a rotor to predict the unbalance in rotor. The vibrations were measured at different speeds using FFT [Fast Fourier Transform], detection of the various effects of vibration signature such as unbalance, misalignment, and crack that may lead to downtime. Vibration analysis therefore helps in monitoring the health of a rotating component. Vibration signature also helps to alert equipment operators of engine health condition. It could be useful to prevent the breakdown [resonance].

Deepak Popat Hujare

School of Mechanical Engineering

Engineering and Technology

S.R. Algule

MIT-World Peace University (MIT-WPU) is a top educational institute located in Pune, India. It is recognized within&nbsp;UGC under Government of Maharashtra Act No. XXXV 2017.&nbsp;

It is part of the MIT group of institutions (established in 1983) which covers 10+ campuses across India and has more than 50,000+ students enrolled across various disciplines at a given point of time. The institute houses 15 schools ranging from Engineering &amp; Technology, Design, Pharmacy, Commerce, Governance among others. It offers undergraduate, postgraduate and PhD programs among different disciplines.&nbsp;

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MIT World Peace University

International journal of emerging engineering research and technology

Mechanical Systems and Signal Processing

Unbalance identification using the least angle regression technique

Unbalance and bow are found to be one of the most common causes of synchronous machinery vibrations in rotating systems. Concentrated lumped mass models are adopted in most of the finite element approach for modeling unbalances and subsequent balancing in rotating systems. But this assumption may not be appropriate for long slender rotors with unbalances distributed along the length of the rotor. A polynomial curve for eccentricity distribution with finite element modeling is used to identify the distributed unbalance. The unbalance eccentricity distributions are estimated using the measured vibration responses at a speed below the balancing speed. Modal correction mass required to balance a rotor at its first bending critical speed, having both distributed unbalance and bow is computed knowing the amplification factor at critical speed. The rotor is balanced at its first bending critical speed using modal balancing method in a single trial run and using a single balancing plane. The method thus avoids multiple trial runs required for modal balancing of flexible rotors. This method is verified on an experimental rotor having both bow and unbalance. The concept of quantifying the distributed unbalance using 'Norm' of eccentricity polynomial function is also introduced for the first time. © 2013 Published by Elsevier Ltd.

Journal of Sound and Vibration

Modal balancing of flexible rotors with bow and distributed unbalance

Measurement

Experimental analysis on fault detection for a direct coupled rotor-bearing system

Procedia Engineering

Study of Effect of Unbalanced Forces for High Speed Rotor

Model based methods for fault identification in rotating systems are gaining importance for the last three decades due to their ability to identify both location and severity of the fault. Model based methods are of different types. Among them, equivalent loads minimization method is one method. In this method, fault is identified in a rotor bearing system by minimizing difference between equivalent loads estimated in the system due to the fault and theoretical fault model loads. This method has a limitation that the error in identified fault parameters increases with decrease in number of measured vibrations. Thus a comprehensive methodology for fault identification with minimum error even in case of fewer measured vibrations is attempted in the present work. Two different approaches: equivalent loads minimization and vibration minimization method are applied for the identification of unbalance fault in a rotor system. Unbalance fault is identified using proposed methods by measuring transverse vibrations at only one location. © 2010 Elsevier Ltd All rights reserved.

Identification of unbalance in a rotor bearing system

Experimental study of unbalance in shaft rotor system using vibration signature analysis

Journal	International journal of emerging engineering research and technology
Publisher	SRYAHWA Publications
Open Access	0