After unbalance, coupling misalignment is the most common fault present in rotating machines. However, limited research has been carried out on coupling misalignment and its effects. The present study aims to explore the research on coupling misalignment by briefly summarizing the research work done so far on different modelling techniques, effects on the system behaviour, fault identification and condition monitoring techniques.

A. Seshadri Sekhar

Department of Mechanical Engineering

G. N.D.S. Sudhakar

Alignment

Condition monitoring

Rotating machinery

COMMON FAULTS

COUPLING MISALIGNMENT

Fault identifications

Modelling techniques

MONITORING TECHNIQUES

Rotating machine

Couplings

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Coupling misalignment in rotating machines: modelling, effects and monitoring

Noise and Vibration Worldwide

Rotor faults such as misalignment, shaft crack, rotor rub, bearing fault etc. lead to high vibration and are major cause of machinery shut down. Misalignment in rotating machinery shafts develops reaction forces and moments at the coupling. Conventionally, misalignment diagnosis is carried through vibration measurements. Especially, the existence of strong 2x component is widely accepted. However, there are other rotor-bearing faults which lead to significant 2x vibrations. Hence distinguishing misalignment is a challenging task using vibration signals alone. In view of these limitations by employing vibrations signals, present study focuses on torque measurements for misalignment diagnosis. Experimental results using torque sensor for different cases of misalignment at different frequency of operation are reported. Fourier and wavelet transforms are used to detect the misalignment fault. The variation of the fault characteristics with respect to time are reported for sampled signals using wavelet transforms. The study shows the possibilities of using torque measurements as useful and additional technique for the detection and monitoring of coupling misalignment. © 2014 Elsevier Ltd. All rights reserved.

Measurement: Journal of the International Measurement Confederation

Detection and monitoring of coupling misalignment in rotors using torque measurements

Improper aligning of shafts through couplings often leads to severe vibration problems in many rotating machines. The rotor-bearing system is modelled using higher order finite elements by considering deflection, slope, shear force, bending moment with eight degrees of freedom per node. The reaction forces, moments developed due to flexible coupling misalignment are derived and introduced in the model. The imbalance response in two harmonics is evaluated. The increase in harmonics with misalignment can easily be modelled by using FEM analysis. The location of the coupling with respect to the bending mode shape has a strong influence on the vibrations. © 1995 Academic Press. All rights reserved.

Journal of Sound and Vibration

Effects of coupling misalignment on vibrations of rotating machinery

Dynamical Systems

Nonlinear Response in a Rotor System With a Coulomb Spline

Mechanical Systems and Signal Processing

Diagnostics of a crack in a load coupling of a gas turbine using the machine model and the analysis of the shaft vibrations

International Journal of Rotating Machinery

Meshing Force of Misaligned Spline Coupling and the Influence on Rotor System

Misalignment in rigidly coupled rotors

Coupling misalignment in rotating machines: Modelling, effects and monitoring

Journal	Noise and Vibration Worldwide
Publisher	Multi-Science Publishing Co. Ltd
ISSN	09574565
Open Access	No