Fundamentals of Rotating Machinery Diagnostics

Fundamentals of Rotating Machinery Diagnostics
اسم المؤلف
Donald E. Bently
1 مارس 2020
(لا توجد تقييمات)

Fundamentals of Rotating Machinery Diagnostics
Donald E. Bently
Chairman of the Board and Chief Executive Officer
Bently Pressurized Bearing Company With
Charles T. Hatch
Edited by
Bently Pressurized Bearing Press
Table of Contents

Fundamentals of Vibration
1 Vibration
The Basic Vibration Signal
Displacement, Velocity, and Acceleration
The Vibration of Machines
Rotation and Precession
Free Vibration
Forced Vibration
Self-Excited Vibration
2 Phase
What is Phase?
Why Is Phase Important?
The Keyphasor Event
Phase Measurement
Absolute Phase
Relative Phase
Differential Phase
3 Vibration Vectors
Unfiltered Vibration
Filtering and the Vibration Vector
Working with Vibration Vectors
The Slow Roll Vector
viiviii Fundamentals of Rotating Machinery Diagnostics
Data Plots
4 Timebase Plots 51
The Structure of a Timebase Plot 52
The Keyphasor Mark 54
Compensation of Timebase Plots 54
Information Contained in the Timebase Plot 56
Summary 66
5 The Orbit 69
The Construction of the Orbit 70
The Keyphasor Mark 72
Compensation of Orbits 74
Information Contained in the Orbit 79
The Orbit/Timebase Plot 94
Summary 95
6 Average Shaft Centerline Plots 97
The Construction of the Average Shaft Centerline Plot 98
Information Contained in the Average Shaft Centerline Plot 101
The Complete Picture: Orbit Plus Average Shaft Centerline Position 108
Summary 109
7 Polar, Bode, and APHT Plots 111
The Structure of Polar and Bode Plots 112
Slow Roll Compensation 115
Information Contained in Polar and Bode Plots 117
APHT Plots 127
Acceptance Region Plots 129
Summary 130
References 130
8 Half and Full Spectrum Plots 131
The Half Spectrum Plot 133
Technical Issues 135
The Full Spectrum 138
Spectrum Cascade Plots 148
Spectrum Waterfall Plots 150
Summary 1539 Trend and XY Plots
Trend Plots
XY Plots
The Static and Dynamic Response of Rotor Systems
10 The Rotor System Model
Introduction to Modeling
The Coordinate System and Position Vector
Lambda (A): A Model of Fluid Circulation
Fluid-film Bearing Forces and Stiffnesses
Other Sources of Spring Stiffness
The Damping Force
The Perturbation Force
The Free Body Diagram
The Equation of Motion
Solution of the Equation of Motion
Nonsynchronous Dynamic Stiffness
Amplitude and Phase of the Vibration Response
The Attitude Angle: Rotor Response to a Static Radial Load
Synchronous Rotor Response
Synchronous Dynamic Stiffness
Predicted Rotor Vibration
The Benefits and Limitations of the Simple Model
Extending the Simple Model
11 Dynamic Stiffness and Rotor Behavior
What Is Dynamic Stiffness?
Rotor Parameters and Dynamic Stiffness
Synchronous Rotor Behavior
Synchronous Behavior Below Resonance
Synchronous Behavior At The Balance Resonance
Synchronous Behavior Above Resonance
221x Fundamentals of Rotating Machinery Diagnostics
How Changes In Dynamic Stiffness Affect Vibration
12 Modes of Vibration
Mode Shapes
Forced Mode Shapes and Multimode Resp onse
Modal Parameters
The Measurement of Mode Shape
Mode Identificat ion Probes
13 Anisotro pic Stiffness
Anisotropic Stiffness
Split Resonances
Measured Rotor Behavior and Anisotropic Stiffness
Probe Mounting Orientation and Measured Resp on se
Virtual Probe Rotation
Forward and Reverse Vectors
14 Rotor Stability Analysis: The Root Locus
What is Stability?
Stability and Dynamic Stiffness
Stability Analysis
State-Space Formulation of th e Eigenvalue Problem
The Root Locus Plot
The Root Locu s and Amplification Factors
Paramet er Variation and the Root Locus
The Root Locu s of Anisotropic and Multimode Systems
The Root Locu s and the Logarithmic Decrement
Th e Root Locus and the Campbell Diagram
Root Locus Analysis of Machine Stability Probl em s
Referen ces
15 Torsional and Axial Vibration
The Torsional View of the Rotor
Static and Dynamic Torsional Response
Torsional/Radial Cross Coupling
326Torsional Vibration Measurement
Axial Vibration
16 Basic Balancing of Rotor Systems
Unbalance and Rotor Response
Vibration Transducers And Balancing
Balancing Methodology
Locating the Heavy Spot Using a Polar Plot
Using Polar Plots Of Velocity and Acceleration Data
Selecting the Calibration Weight
Relating Balance Ring Location To Polar Plot Location
Single Plane Balancing With Calibration Weights
Weight Splitting
The Influence Vector
The Influence Vector And Dynamic Stiffness
Multiple Modes And Multiplane Balancing
Multiplane Balancing With Influence Vectors
How Balancing Can Go Wrong
17 Introduction to Malfunctions
What is a Malfunction?
Detection of Malfunctions
18 Unbalance
Rotor System Vibration Due To Unbalance
Stress and Damage
Other Things That Can Look Like Unbalance
Rotor Bow
Electrical Noise in the Transducer System
Coupling Problems
Shaft Crack
Loose Part or Debris
399xii Fundamentals of Rotating Machinery Diagnostics
Changes in Spring Stiffness
Electric Motor Related Problems
Loose Rotating Parts
19 Rotor Bow
What is Rotor Bow?
Causes of Rotor Bow
Rotor Dynamic Effects of Rotor Bow
Thermal Bow During Operation
Diagnosing Rotor Bow
Removing Rotor Bow
20 High Radial Loads and Misalignment
Static Radial Loads
What Is Misalignment?
Temperature Changes and Alignment
Causes of Misalignment
Symptoms of High Radial Load and Misalignment
Bearing Temperature
Vibration Changes
Stresses and Wear
Abnormal Average Shaft Centerline Position
Orbit Shape
Fluid-Induced Instability
21 Rub and Looseness
Rub and Looseness
Partial Radial Rub
Full Annular Rub
Rub-Induced Forces and Spring Stiffness Changes
Rub and Steady State IX Vibration
Rub and IX Vibration During Resonance
Subsynchronous Vibration
Symptoms of Rub
Other Malfunctions with Similar Symptoms 470
Summary 473
22 Fluid-Induced Instability 475
The Cause of Fluid-Induced Instability 476
Modes of Instability: Whirl and Whip 480
Symptoms of Fluid-Induced Instability 486
Other Malfunctions That Can Produce Similar Symptoms 488
Locating the Source of Instability 492
Eliminating Fluid-Induced Instability 492
Summary 496
23 Externally Pressurized Bearings and Machinery Diagnostics 499
Types of Bearings 499
Internally Pressurized Fluid-Film Bearings 500
Externally Pressurized Fluid-Film Bearings 501
Stiffness and Modal Damping in Fluid-Film Bearings 503
Variable Stiffness in Internally Pressurized Bearings 504
Variable Stiffness in Externally Pressurized Bearings 508
Rotor Dynamic Implication of Variable Stiffness Bearings 509
Diagnostic Implications of Variable Stiffness Bearings 512
Summary 514
References 515
24 Shaft Cracks 517
Crack Initiation, Growth, and Fracture 517
Reduction of Shaft Stiffness Due To a Crack 520
Shaft Asymmetry and 2X Vibration 522
The First Rule of Crack Detection (IX) 524
The Second Rule of Crack Detection (2X) 526
Other Malfunctions That Produce IX Vibration Changes 529
Other Malfunctions That Produce 2X Vibration 530
Design and Operating Recommendations 530
Monitoring Recommendations 531
Summary 532xiv Fundamentals of Rotating Machinery Diagnostics
Case Histories
25 High Vibration in a Syngas Compressor Train
Steady State Analysis
Transient Data Analysis
Inspection and Modification of the Machine
26 Chronic High Vibration in a Draft Fan
The First Balancing Attempt
The Real Problem
27 A Generator Vibration Puzzle
Unusual Vibration Behavior
Data Analysis
28 High Vibration in an Electric Motor
Data Analysis
29 Problems with a Pipeline Compressor
The Machine Train
Tests With Pinned Seals
Tests With Unpinned Seals
Tests With Damper Bearing
Additional Analysis
Conclusions and Recommendations
Al Phase Measurement Conventions
The Instrumentation Convention
The Mathematical Convention
Converting Between The Two Conventions
Phase On Bode and APHT Plots
603A2 Filtered Orbit and Timebase Synthesis
Timebase Synthesis
Orbit Synthesis
A3 The Origin of the Tangential Stiffness Term
Modeling the Pressure Wedge
Tra nsformation to Stationary Coordinates
A4 SAF Calculation
Peak Ratio Method
Phase Slope Method
Polar Plot Method
A5 Vector Transforms
Virtual Probe Rotation
The Forward and Reverse Tran sform and Full Spectrum
A6 Eigenvalues of the Rotor Model
The Threshold of Instability
A7 Units of Measurement
Metric/US Customary Unit Conversions
Unit Prefixes
Unit Abbreviations
Force. Weight, and Mass in the US Customary System
AS Nomenclature
Upper case Roman
Lower case Roman
Upper case Greek
Lower case Greek
About the Authors
About Bently Nevada
Table of Contents xv
كلمة سر فك الضغط :
The Unzip Password :


يجب عليك التسجيل في الموقع لكي تتمكن من التحميل
تسجيل | تسجيل الدخول


اترك تعليقاً