An analysis method for the vibration signal with amplitude modulation in a bearing system

2007 ◽  
Vol 303 (3-5) ◽  
pp. 538-552 ◽  
Author(s):  
Yuh-Tay Sheen
Keyword(s):  
Amplitude Modulation ◽  
Vibration Signal ◽  
Analysis Method ◽  
Bearing System

Systematical Analysis Method for the Mechanical Behaviors of Crankshaft-Bearing System

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Changlin Gui ◽  
Jun Sun ◽  
Zhixian He ◽  
Zhen Li
Keyword(s):  
Elastic Deformation ◽  
Dynamic Stress ◽  
Analysis Method ◽  
Mechanical Behaviors ◽  
Remarkable Effect ◽  
Journal Misalignment ◽  
Bearing System

Various mechanical behaviors will happen at the same time when an engine operates. Based on this concept, in this paper, a systematical analysis method is presented to analyze the multiple mechanical behaviors (tribology, dynamics, stiffness, and strength) of the crankshaft-bearing system in an engine. By this method, the analyses of the tribology of bearing, the dynamics of crankshaft-bearing system and the dynamic stress of crankshaft can be accomplished simultaneously. For example, the effect of the journal misalignment of crankshaft and the elastic deformation of bearing bush on the dynamics of crankshaft-bearing system, the tribological performances of main bearings and the dynamic stress of crankshaft are analyzed emphatically. The results show that the journal misalignment of crankshaft and the elastic deformation of bearing bush have remarkable effect on the tribological performances of main bearings and the dynamic stress of crankshaft, but have little effect on the dynamics of crankshaft-bearing system.

scholarly journals Analytical and Numerical Investigation on the Duffing Oscilator Subjected to a Polyharmonic Force Excitation

2015 ◽  
Vol 45 (1) ◽  
pp. 3-16 ◽  
Author(s):  
Svetlin Stoyanov
Keyword(s):  
Fourier Transform ◽  
Analytical Solution ◽  
Discrete Time ◽  
Amplitude Modulation ◽  
Duffing Oscillator ◽  
Vibration Signal ◽  
Vibration Diagnostics ◽  
Significant Difference ◽  
Excitation Force ◽  
Force Excitation

Abstract An analytical solution for a specific case of the forced Duffing oscillator is proposed. The excitation force contains two harmonics with significant difference frequencies. This case corresponds to a presence of a defect in the machinery and is in the art of the machinery vibration diagnostics. The results obtained show an amplitude modulation. Therefore, the presence of an amplitude modulation in the vibration signal may be used as an indicator for a malfunction. Analytical solution derived clarifies how the amplitude modulation occurs. Also, a numerical solution is realized and compared with the analytical one. For this, the Duffing equation is solved numerically and then, the spectrograms of vibrations are obtained through a Discrete-time Fourier Transform.

Mine Ventilator Fault Diagnosis Based on Harmonic Wavelet Analysis

2011 ◽  
Vol 143-144 ◽  
pp. 613-617
Author(s):  
Shuang Xi Jing ◽  
Yong Chang ◽  
Jun Fa Leng
Keyword(s):  
Fault Diagnosis ◽  
Wavelet Analysis ◽  
Frequency Domain ◽  
Vibration Signal ◽  
Wavelet Function ◽  
Frequency Region ◽  
Analysis Method ◽  
Vibration Signals ◽  
Harmonic Wavelet ◽  
Frequency Components

Harmonic wavelet function, with the strict box-shaped characteristic of spectrum, has strong ability of identifying signal in frequency domain, and can extract weak components form vibration signals in frequency domain. Using harmonic wavelet analysis method, the selected frequency region and other frequency components of vibration signal of mine ventilator were decomposed into independent frequency bands without any over-lapping or leaking. Simulation and diagnosis example show that this method has good fault diagnosis effect, and the ventilator fault is diagnosed successfully.

An analysis method to determine how changes in dynamic complexity impact on rotor-bearing systems

2020 ◽  
pp. 095440622095488
Author(s):  
Mian Jiang ◽  
Shuangqi Liu ◽  
Yuhua Wang
Keyword(s):  
Condition Monitoring ◽  
Lubricating Oil ◽  
Analysis Method ◽  
Dynamic Complexity ◽  
Rotor Systems ◽  
Methodological Choices ◽  
Rotor Bearing ◽  
Nonlinearity Measures ◽  
Monitoring Performance ◽  
Bearing System

Condition monitoring performance and diagnosis of rotor-bearing systems depend not only on the methods used, but also on the dynamic complexity of the system itself. Thus, it is important to analyze how changes in parameters under various working conditions impact on dynamic complexity. Most of previous research efforts on this topic have been focused on the analysis of nonlinear dynamics of rotor-bearing systems with different parameters. In this paper, a nonlinearity quantification based analysis method is presented to determine how parameter dynamics impact the complexity of rotor-bearing systems. The dynamic complexity of rotor system is estimated using defined nonlinearity measures. To validate this method, a sliding rotor-bearing system with a loose pedestal is used. The estimates (nonlinearity degrees) and the states of motion are matched with increasing rotational speeds. It is then investigated, how the eccentricities, lubricating oil viscosities, and bearing clearances impacted the dynamic complexity at several critical rotational speeds. These results can guide methodological choices for condition monitoring and diagnosis of rotor systems.

A Rolling Bear Fault Diagnosis Method Based on Improved LMD and Order Analysis

2014 ◽  
Vol 530-531 ◽  
pp. 256-260
Author(s):  
Hui Juan Yuan ◽  
Jia Qi ◽  
Hong Mei Li ◽  
Jun Zhong Li ◽  
Xue Jiang ◽  
...  
Keyword(s):  
Fault Diagnosis ◽  
Amplitude Modulation ◽  
Frequency Modulation ◽  
Rolling Bearing ◽  
Analysis Method ◽  
Vibration Signals ◽  
Order Analysis ◽  
Diagnosis Method ◽  
Bearing Vibration

This document explains and demonstrates how to predict the fault point of rolling bear. Rolling bearing vibration signals are decomposed by the LMD method to get several single components including amplitude modulation and frequency modulation signals. Combing the order analysis method can get the fault point of rolling bear.

The Damped Eigenfrequency Analysis for an Elastic Disk Clamped by a Water-Filled Cylinder

2012 ◽  
Vol 490-495 ◽  
pp. 3742-3747
Author(s):  
Zhi Xi Yang
Keyword(s):  
Signal Analysis ◽  
Effective Means ◽  
Three Dimensional ◽  
Vibration Signal ◽  
Analysis Method ◽  
Obvious Effect ◽  
Coupled Numerical Model ◽  
Elastic Disk ◽  
Vibration Signal Analysis ◽  
Signal Analysis Method

A vibroacoustic testing model in laboratory for the damped eigenfrequencies and eigenmodes is introduced in this paper. The unsymmetric (u, p) variational formulas are implemented for three dimensional structures based on the elastodynamic displacement field u and the fluid acoustic pressure field p. The damping coefficients of materials seem to have no obvious effect on the coupled numerical model. Then the damped eigenfrequencies can alternately be obtained by vibration signal analysis method. The Fast Fourier Transform for the spectrum domain analysis illustrates an effective means to evaluate the damped eigenfrequencies.

Comparison of Effects of Dimensional Manufacturing Tolerances and Journal Out-of-Roundness on Stability of Hydrodynamic Journal Bearing System

2011 ◽  
Vol 121-126 ◽  
pp. 1966-1971
Author(s):  
Wu Bin Xu ◽  
De Jian Zhou ◽  
Peter Ogrodnik ◽  
Mike Goodwin
Keyword(s):  
Theoretical Analysis ◽  
Taguchi Method ◽  
Journal Bearing ◽  
Journal Bearings ◽  
System Stability ◽  
Design Stage ◽  
Analysis Method ◽  
Manufacturing Tolerances ◽  
Hydrodynamic Journal Bearing ◽  
Bearing System

The manufacturing tolerances of a hydrodynamic journal bearing system are inevitable in manufacturing process. To examine and understand the effect of manufacturing tolerances on the system stability can help engineers to confidently choose reasonable tolerances at design stage. This study presented a theoretical analysis method to determine and compare the effects of dimensional manufacturing tolerances and journal out-of-roundness on system stability by Taguchi method. The results show that the journal out-of-roundness has the most significant effect on the system stability and the journal out-of-roundness appears to stabilize the system. The authors suggest that both dimensional manufacturing tolerances and journal roundness should be taken into account in the design of cylindrical journal bearings.

Research on a vibration signal analysis method for motor bearing

Optik ◽  
2016 ◽  
Vol 127 (20) ◽  
pp. 10014-10023 ◽  
Author(s):  
Huimin Zhao ◽  
Wu Deng ◽  
Xinhua Yang ◽  
Xiumei Li
Keyword(s):  
Signal Analysis ◽  
Vibration Signal ◽  
Analysis Method ◽  
Vibration Signal Analysis ◽  
Signal Analysis Method ◽  
Motor Bearing

Auxiliary Bearing System Optimization for AMB Supported Rotors Based on Rotor Drop Analysis: Part I — Rotor Drop Analysis Method

2016 ◽  
Author(s):  
Jianming Cao ◽  
Paul Allaire ◽  
Timothy Dimond ◽  
Saeid Dousti
Keyword(s):  
Ball Bearing ◽  
System Optimization ◽  
American Petroleum Institute ◽  
Operating Conditions ◽  
Rolling Element Bearing ◽  
Hertzian Contact ◽  
Analysis Method ◽  
Contact Loads ◽  
Auxiliary Bearing ◽  
Bearing System

For rotors supported with active magnetic bearings (AMBs), the auxiliary bearing system or backup bearing system is needed to avoid serious potential internal damaging in the event of AMB loss of power or overload. The evolution of auxiliary systems has been made a priority by the American Petroleum Institute using analytical or experimental methods. In part I of this paper, a detailed rotor drop nonlinear transient analysis method including flexible shaft, rolling element bearing components including inner/outer races and balls, as well as flexible/damped supporting structures is given. A finite element based 6-DOF flexible rotor model is used to indicate shaft motion before the drop (operating conditions) and during the rotor drop event. Un-lubricated Hertzian contact models are used between the shaft and inner/outer races, between balls and races. To avoid heavy calculating time, two different methods to calculate ball bearing contact loads are discussed and the simulation results are compared. These models are applied to predict shaft-race-ball displacements and angular speeds, contact loads and ball bearing stresses during the drop for angular contact auxiliary bearings. This method also can be used to design and optimize the auxiliary bearing system as presented in the 2nd part of this paper.

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