The effects of the operating conditions and tooth fault on gear vibration signature

2021 ◽  
Vol 154 ◽  
pp. 107508
Author(s):  
Lior Bachar ◽  
Ido Dadon ◽  
Renata Klein ◽  
Jacob Bortman
Keyword(s):  
Operating Conditions ◽  
Vibration Signature

scholarly journals Full-Scale Wind Turbine Vibration Signature Analysis

Machines ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 63 ◽  
Author(s):  
Xavier Escaler ◽  
Toufik Mebarki
Keyword(s):  
Wind Farm ◽  
Power Spectra ◽  
Operating Conditions ◽  
Drive Train ◽  
Normal Operation ◽  
Common Source ◽  
Variable Speed ◽  
Data Set ◽  
Vibration Signature ◽  
Power Curves

A sample of healthy wind turbines from the same wind farm with identical sizes and designs was investigated to determine the average vibrational signatures of the drive train components during normal operation. The units were variable-speed machines with three blades. The rotor was supported by two bearings, and the drive train connected to an intermediate three-stage planetary/helical gearbox. The nominal 2 MW output power was regulated using blade pitch adjustment. Vibrations were measured in exactly the same positions using the same type of sensors over a six-month period covering the entire range of operating conditions. The data set was preliminary validated to remove outliers based on the theoretical power curves. The most relevant frequency peaks in the rotor, gearbox, and generator vibrations were detected and identified based on averaged power spectra. The amplitudes of the peaks induced by a common source of excitation were compared in different measurement positions. A wind speed dependency of broadband vibration amplitudes was also observed. Finally, a fault detection case is presented showing the change of vibration signature induced by a damage in the gearbox.

Enhancement of Turning Process Using Vibration Signature Analysis

2005 ◽  
Author(s):  
Marlon C. Batey ◽  
Hamid R. Hamidzadeh
Keyword(s):  
Manufacturing Process ◽  
Vibration Analysis ◽  
Manufacturing System ◽  
Cutting Tool ◽  
Operating Conditions ◽  
Turning Process ◽  
Analysis Problem ◽  
Frequency Domains ◽  
Vibration Signature ◽  
Vibration Signatures

Analytical and experimental vibration analyses are conducted for a lathe system to detect the possibility of faults and develop an accurate cutting process. The data acquisition system utilized for this purpose processes the analog input from the manufacturing system and displays the response in both the real time and frequency domains. The vibration signatures for different arrangements are recorded to determine the dynamic characteristics of the system which includes work pieces, tool, and lathe components. These vibration signatures were analyzed to determine cause of inaccuracy in the manufacturing process and the faulty components. In this study, two major problem causing sources were identified using vibration analysis for the system under different operating conditions. In addition to the identified problems, the phenomena of cutting tool chatter with various intensities was examined and recorded during testing. In this study the best possible operating conditions for a specific turning process were determined using vibration analysis. Problem causing components for several case studies (different speeds, feed rates, and tool lengths) were identified and guidelines for improving a typical manufacturing process were recommended.

Enhancement of Vehicle Wheel Vibration Level by using active Camber angle based on a Double Wishbone System

2019 ◽  
Vol 11 (2) ◽  
Author(s):  
A.S. Emam ◽  
Eid S. Mohamed
Keyword(s):  
Normal Load ◽  
Vibration Signal ◽  
Wheel Speed ◽  
Suspension System ◽  
Operating Conditions ◽  
Active System ◽  
Camber Angle ◽  
Vibration Signature ◽  
Arduino Microcontroller ◽  
Wheel Vibration

Active camber angle position systems for vehicle wheel alignments can better regulate the wheel camber angle position in different operating conditions of vehicles. The aim of this work is to illustrate the application of active camber angle position theory. A prototype of one wheel equipped by the double wishbone suspension system and the variable camber angle control with suspension system concept is proposed. Active camber system uses a linear actuator with Arduino microcontroller. A comparative study was done on wheel vibration characteristics of the conventional camber system (passive system) and active system. The experimental results and analysis show that the vibration signature is influenced by the camber angle position. It is found that the vibration signal increases when the vehicle wheel speed and normal load are increased. Moreover, the results indicate that the root mean square (RMS) of vehicle wheel vibration is improved by 17.78%, 38.6% and 49.63% at wheel speed of 250 rpm, 500 rpm and 750 rpm respectively by using the proposed active camber angle. The vehicle wheel vibration behaviour with active camber angles is likely to be optimum under the different wheel operating conditions.

Transient and Steady State Vibration Analysis of a Wavy Thrust Bearing

2005 ◽  
Vol 128 (1) ◽  
pp. 139-145 ◽  
Author(s):  
H. Zhao ◽  
F. K. Choy ◽  
M. J. Braun
Keyword(s):  
Steady State ◽  
Vibration Analysis ◽  
Thrust Bearing ◽  
Numerical Procedure ◽  
Operating Conditions ◽  
System Stability ◽  
Thrust Bearings ◽  
External Perturbations ◽  
Vibration Signature ◽  
Transient And Steady State

This paper describes a numerical procedure for analyzing the dynamics of transient and steady state vibrations in a wavy thrust bearing. The major effects of the wavy geometry and the operating parameters on the dynamic characteristics of the bearing had been discussed in a previous paper; the present paper thus concentrates on examining the relationships between the development of the transient and steady state vibrations when operating conditions are parametrically varied. Special attention is given to the development of steady state vibrations from initial transients with comparisons and consequences to the overall system stability. Numerical based vibration signature analysis procedures are then used to identify and quantify the transient vibrations. The conclusions provide general indicators for designing wavy thrust bearings that are less susceptible to transients induced by external perturbations.

scholarly journals Improved effectiveness of vibration monitoring of rolling bearings in paper mills

1998 ◽  
Vol 212 (2) ◽  
pp. 111-120 ◽  
Author(s):  
B Al-Najjar
Keyword(s):  
Critical Role ◽  
Paper Mill ◽  
Operating Conditions ◽  
Rolling Element Bearing ◽  
Vibration Monitoring ◽  
Paper Mills ◽  
Bearing Failures ◽  
Study Results ◽  
Rolling Element ◽  
Vibration Signature

Rolling element bearing failures in paper mill machines are considered in relation to their critical role in the machine function. The paper discusses these failures according to what becomes damaged and how, and relates them to the vibration spectra and their development over the lives of the bearings. Interpretations of some variations in the vibration signature, i.e. relating vibration amplitude changes and frequency shifts to the deterioration processes involved, are proposed and discussed. The literature was found mainly to confirm this analysis. A new approach to envelope alarming is presented and shown theoretically (logically) to offer later renewal with fewer failures, and therefore lower cost and higher productivity. Deficiencies in data coverage and quality, and the feedback of case study results, are discussed. A model to improve maintenance experience is proposed and discussed. Using vibration to monitor component conditions, the accurate prediction of remaining life requires (a) enough vibration measurements, (b) numerate records of operating conditions, (c) better discrimination between frequencies in the spectrum and (d) correlation of (b) and (c). This is because life prediction depends on the amplitudes of (and) the frequencies generated by the component damage. Much money could be saved because some of the present policies utilize as little as half of the useful life of a bearing.

An overview of dynamic modeling of rolling-element bearings

2020 ◽  
pp. 095745652094827
Author(s):  
Surajkumar G Kumbhar ◽  
Edwin Sudhagar P ◽  
RG Desavale
Keyword(s):  
Dynamic Behavior ◽  
Dynamic Modeling ◽  
Operating Conditions ◽  
Rolling Element Bearing ◽  
Rolling Element Bearings ◽  
Roller Bearings ◽  
Rolling Element ◽  
Vibration Responses ◽  
Vibration Signature ◽  
Element Bearing

The marvelous uniqueness of vibration responses of faulty roller bearings can be simply observed through its vibration signature. Therefore, vibration analysis has been claimed as an effective tool not only for primitive detection but also for subsequent analysis. The dynamic behavior of roller bearings has been investigated by systematic modeling of system and its validation under diverse operating conditions. This article presents an overview of imperative marks in the development of dynamic modeling of rolling-element bearing, which especially predicted vibration responses of damaged bearings. This study aims to address dimensional analysis; a new and imperative way to model the dynamic behavior of rolling-element bearings and their real-time performance in a rotor-bearing system. The findings are described with influential advantages over earlier research to pinpoint the intention behind its development. A literature summary is trailed by remarkable findings and future directions for research.

Effects of Gear Box Vibration and Mass Imbalance on the Dynamics of Multistage Gear Transmission

1991 ◽  
Vol 113 (3) ◽  
pp. 333-344 ◽  
Author(s):  
F. K. Choy ◽  
Y. K. Tu ◽  
J. J. Zakrajsek ◽  
D. P. Townsend
Keyword(s):  
Dynamic Behavior ◽  
Operating Conditions ◽  
Gear Transmission ◽  
Mode Shapes ◽  
Torsional Vibrations ◽  
Mass Imbalance ◽  
Gear Mesh ◽  
Multi Stage ◽  
Vibration Signature ◽  
Gear Box

The objective of this paper is to present a comprehensive approach to analyze the dynamic behavior of multi-stage gear transmission systems with the effects of gear box induced vibrations and rotor mass-imbalances. The modal method, using undamped frequencies and planar mode shapes, is used to reduce the degree of freedom of the system. The various rotor-bearing stages as well as the lateral and torsional vibrations of each individual stage are coupled through localized gear mesh tooth interactions. Gear box vibrations are coupled to the gear stage dynamics through bearing support forces. Transient and steady state dynamics of lateral an torsional vibrations of the geared system are examined in both time and frequency domains. Vibration signature analysis techniques will be developed to interpret the overall system dynamics and individual modal excitations under various operating conditions. A typical 3- staged geared system is used as an example. Effects of mass imbalance and gear box vibrations on the system dynamic behavior are presented in terms of modal excitation functions for both lateral and torsional vibrations. Operational characteristics and conclusions are drawn from the results presented.

Transient and Steady State Vibration Analysis of a Wavy Thrust Bearing

2004 ◽  
Author(s):  
Hongmei Zhao ◽  
F. K. Choy ◽  
M. J. Braun
Keyword(s):  
Steady State ◽  
Vibration Analysis ◽  
Thrust Bearing ◽  
Numerical Procedure ◽  
Operating Conditions ◽  
System Stability ◽  
Thrust Bearings ◽  
External Perturbations ◽  
Vibration Signature ◽  
Transient And Steady State

This paper describes a numerical procedure for analyzing the dynamics of transient and steady state vibrations in a wavy thrust bearing. The major effects of the wavy geometry and the operating parameters on the dynamic characteristics of the bearing had been discussed in previous work. The present study thus concentrates on examining the relationships between the development of the transient and steady state vibrations when operating conditions including rotational speed and load magnitude are parametrically varied. Special attention is given to the development of steady state vibrations from initial transients with comparisons and consequences to the overall system stability. Numerical based vibration signature analysis procedures are then used to identify and quantify the transient vibrations. The conclusions provide general indicators for designing wavy thrust bearings that are less susceptible to transients induced by external perturbations.

Cathodoluminescence of Catalyst Crystallites

1982 ◽  
Vol 40 ◽  
pp. 664-665
Author(s):  
E.D. Boyes ◽  
P.L. Gai ◽  
D.B. Darby ◽  
C. Warwick
Keyword(s):  
Defect Density ◽  
Chemical Properties ◽  
Operating Conditions ◽  
Semiconductor Materials ◽  
Environmental Cell ◽  
High Resolution Structure ◽  
Commercially Important ◽  
Crystallographic Defects ◽  
Resolution Structure

The extended crystallographic defects introduced into some oxide catalysts under operating conditions may be a consequence and accommodation of the changes produced by the catalytic activity, rather than always being the origin of the reactivity. Operation without such defects has been established for the commercially important tellurium molybdate system. in addition it is clear that the point defect density and the electronic structure can both have a significant influence on the chemical properties and hence on the effectiveness (activity and selectivity) of the material as a catalyst. SEM/probe techniques more commonly applied to semiconductor materials, have been investigated to supplement the information obtained from in-situ environmental cell HVEM, ultra-high resolution structure imaging and more conventional AEM and EPMA chemical microanalysis.

Comparison of Deterministic and Linear Cosine Spatial Filtering of Transmission Electron Micrographs

1972 ◽  
Vol 30 ◽  
pp. 596-597
Author(s):  
David A. Ansley
Keyword(s):  
Spherical Aberration ◽  
Focal Length ◽  
Chromatic Aberration ◽  
Spatial Filter ◽  
Operating Conditions ◽  
Objective Lens ◽  
List Type ◽  
Spatial Filters ◽  
Transmission Electron ◽  
Wide Range

The coherence of the electron flux of a transmission electron microscope (TEM) limits the direct application of deconvolution techniques which have been used successfully on unmanned spacecraft programs. The theory assumes noncoherent illumination. Deconvolution of a TEM micrograph will, therefore, in general produce spurious detail rather than improved resolution.A primary goal of our research is to study the performance of several types of linear spatial filters as a function of specimen contrast, phase, and coherence. We have, therefore, developed a one-dimensional analysis and plotting program to simulate a wide 'range of operating conditions of the TEM, including adjustment of the:(1) Specimen amplitude, phase, and separation(2) Illumination wavelength, half-angle, and tilt(3) Objective lens focal length and aperture width(4) Spherical aberration, defocus, and chromatic aberration focus shift(5) Detector gamma, additive, and multiplicative noise constants(6) Type of spatial filter: linear cosine, linear sine, or deterministic

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