Lugt Piet M. Grease Lubrication in Rolling Bearings

John Wiley & Sons, Ltd., 2013. 459 p. — ISBN: 978-1-118-35391-2 — (Tribology in Practice Series).The definitive book on the science of grease lubrication for roller and needle bearings in industrial and vehicle engineering.Grease Lubrication in Rolling Bearings provides an overview of the existing knowledge on the various aspects of grease lubrication (including lubrication systems) and the state of the art models that exist today. The book reviews the physical and chemical aspects of grease lubrication, primarily directed towards lubrication of rolling bearings.The first part of the book covers grease composition, properties and rheology, including thermal and dynamics properties. Later chapters cover the dynamics of greased bearings, including grease life, bearing life, reliability and testing. The final chapter covers lubrications systems – the systems that deliver grease to the components requiring lubrication.Grease Lubrication in Rolling Bearings:Describes the underlying physical and chemical properties of grease.
Discusses the effect of load, speed, temperature, bearing geometry, bearing materials and grease type on bearing wear.
Covers both bearing and grease performance, including thermo-mechanical ageing and testing methodologies.It is intended for researchers and engineers in the petro-chemical and bearing industry, industries related to this (e.g. wind turbine industry, automotive industry) and for application engineers. It will also be of interest for teaching in post-graduate courses.Series Preface
List of AbbreviationsWhy Lubricate Rolling Bearings?
History of Grease Lubrication
Grease Versus Oil LubricationLubrication MechanismsDefinition of Grease
Operating Conditions
The Phases in Grease Lubrication
Film Thickness During the Bleeding Phase
Ball Bearings
Roller Bearings
Feed and Loss Mechanisms During the Bleeding Phase
Film Thickness and Starvation (Side Flow)
Track Replenishment
Grease Flow
Non-Newtonian Rheology
Wall-Slip
Oxidation
EP Additives
Dynamic Behaviour
Grease Life
Temperature
Speed
Load
Bearing Type
Grease Type
EnvironmentGrease Composition and Properties
Base Oil
Natural Triglyceride and Wax Ester Base Oils
Mineral Oils
Synthetic Oils
Base Oil Viscosity and Density
Viscosity–Temperature
Viscosity–Pressure–Temperature
Density, Compressibility
Thickener
Soap Greases, Simple Greases
Complex Greases
Non-soap Thickeners
Mixed Thickeners
Mechanical Structure
Oil Retention
Properties of Different Types of Grease Thickeners
Additives
Corrosion Inhibitors
Antioxidants
EP/AW Additives
Solid Fillers/Dry Lubricants
MoS2 and Graphite
Nanoparticles
ZnO
Teflon (polytetrafluoroethylene)
Polyethylene
Compatibility
Polymer GreaseGrease Life in Rolling BearingsRelubrication Intervals and Grease Life
The Traffic Light Concept
Low Temperatures
Extreme Low Temperature
Extreme High Temperature
Grease Life as a Function of Temperature in the Green Zone
SKF Relubrication and Grease Life
Comparison Grease Life/Relubrication Models
Very Low and High Speeds
Speed Ratings and Speed Factors
High Speed
Very Low Speeds
Large Rolling Bearings
Effect of Load
Varying Load
Direction of Load
Very Heavy Loads
Effect of Outer-Ring Rotation
Cage Material
Bearing Type
Roller Bearings
Hybrid Bearings
Temperature and Bearing Material
Grease Fill
Vertical Shaft
Vibrations and Shock Loads
Grease Shelf Life/Storage LifeLubricating Grease Rheology
Visco-Elastic Behaviour
Viscometers
Parallel Plate and Cone-Plate Viscometers
Errors in Rheometry Measurements
Errors in Thin Film Parallel Plate Rheometry Measurements
Oscillatory Shear
Theory
Application to Grease
Effect of Thickener Concentration
Shear Thinning and Yield
Grease
Lubricating Oil
Yield Stress
The Concept
Influence of Temperature
Consistency
Wall-Slip Effects
Translation Between Oscillatory Shear and Linear Shear Measurements
Viscosity
Yield Stress
Normal stresses
Time Dependent Viscosity and Thixotropy
TackinessTackifiers
Pull-Off Test
Other TestsGrease and Base Oil Flow
Grease Flow in Pipes
Approximation Using the Newtonian Pipe Flow Equations
Non-Newtonian Fluid
Bingham Rheology
Sisko Rheology
Power Law Rheology
Herschel–Bulkley Rheology
The Darcy Friction Factor
Transient Effects
Air in Grease
Entrance Length
Solid Particles in Grease Flow
Wall-Slip/Slip Layer
Impact of Roughness
Grease Aging in Pipes
Grease Flow in Rolling Bearings
Churning
Flow Through Bearing Seals
Relubrication
Grease Flow Around Discontinuities
Creep Flow
Flow Induced by VibrationsGrease BleedingBall Versus Roller Bearings
Grease Bleeding Measurement Techniques
Bleeding from the Covers and Under the Cage
A Grease Bleeding Model for Pressurized Grease by Centrifugal Forces
Oil Bleeding Model
Quality of the ModelGrease Aging
Mechanical Aging
Softening of Grease in Rolling Bearings
Hardening of Grease in Rolling Bearings
Grease Oxidation
The Chemistry of Base Oil Film Oxidation
Chemical Reactions
Oxidation of the Thickener
A Simple Model for Base Oil Degradation
Polymerization
Evaporation
Simple Models for the Life of Base Oil
Booser’s Oil Life Model
Two Phase ModelFilm Thickness Theory for Single Contacts
Elasto-Hydrodynamic Lubrication
History
The Navier–Stokes Equations
The Reynolds and Thin Film Equation
Cavitation
Contact Geometry and Deformation
Rigid Bodies
Elastic Deformation
EHL Film Thickness, Oil
Example: 6204 Bearing
EHD Film Thickness, Grease
Measurements
Film Thickness Models for Grease Rheology
Starvation
Starved Oil Lubricated Contacts
Starved Lubrication EHL Models
Base Oil Replenishment
Starved Grease Lubricated Contacts
SpinFilm Thickness in Grease Lubricated Rolling Bearings
Thin Layer Flow on Bearing Surfaces
Contact Replenishment in Bearings
Thin Layer Flow Induced by Centrifugal Forces
Combining the Thin Layer Flow on the All Bearing Components
Starved EHL for Rolling Bearings
Central Film Thickness
Combining Lightly Starved and Severely Starved
Cage Clearance and Film Thickness
Full Bearing Film ThicknessGrease DynamicsGrease Reservoir Formation
Temperature Behaviour
Temperature and Film Breakdown
Chaotic Behaviour
Reconstruction of the Temperature Dynamics Using Time Delayed Embedding
Estimation of the Time Delay τ
Calculation of the Dimensions d and m
Calculation of the Lyapunov Exponents
Quantitative Analysis of Grease Tests
DiscussionReliability
Failure Distribution
Mean Life and Time Between Failures
Percentile Life
Point and Interval Estimates
Graphical Methods for Point Estimates
Suspended Tests, Censored Data
Weibull Parameters η and β: Maximum Likelihood Method
Bias of Point Estimates
Confidence Intervals for β
Confidence Intervals and Unbiased Point Estimates for Life Percentiles
Estimate Precision
Sudden Death Testing
Maximum Likelihood Method for a 3-Parameter Weibull Distribution
System Life PredictionGrease Lubrication and Bearing Life
Bearing Failure Modes
Rated Fatigue Life of Grease Lubricated Rolling BearingsThe Lubrication Factor
The Contamination Factor ηc
The Stress-Life Modification Factor aslf
Background of the Fatigue Life Ratings of Grease Lubricated Bearings
Fatigue Life and Endurance Testing in the Period 1940–1960
Fatigue Life and Endurance Testing After 1960
The Reliability of Grease Lubricated Bearings
Lubricant Chemistry and Bearing Life
Anti-Wear Additives
EP Additives
The Influence of Lubricant Additives on Bearing Life
Water in GreaseFilm Thickness
Water in Oil and Bearing Life
Concentration of Water
Water in Grease
Surface Finish Aspects Related to Grease LubricationGrease Lubrication Mechanisms in Bearing SealsLubrication Mechanisms for Elastomer Contact Seals
Sealing Action of Grease
Migration of Contaminant Particles in the Pocket
Migration of Contaminant Particles in the Vicinity of the Sealing Contact
Softening and Leakage
Compatibility
A Film Thickness Model for Bearing Seals
Oil Feed
Oil Loss
Some Examples Showing the Importance of Sealing and GreaseCondition Monitoring and Maintenance
Condition Monitoring
Vibrations and Acoustic Emission
Lubcheck
Consistency Measurement
Oil Bleeding Properties
Oil Content
Particle Contamination
Spectroscopy
Infrared (IR) Spectroscopy
Linear Voltammetry
Total Acid Number
DSC – Differential Scanning Calorimetry
Oxidation Bomb
WaterGrease Qualification TestingStandard Test Methods
Penetration/Grease Consistency
Worked Penetration
Shell Roll Stability
Dropping Point
Emcor
Oil Separation
Water Resistance
Low Temperature Torque
Flow Pressure
Ball Weld Load
Ball Wear Scar
High Speed Grease Life Testing, RHF1
R0F
R0F+
R2F, Using the Special Spherical Roller Bearing
R2F, Using Standard Bearings
F
FE8
FE9
A-Frame Cycle Test
Cold Chamber Test
BeQuiet+
Fafnir Friction Oxidation Test
Copper Corrosion Test
EP Reaction Test
Compatibility with Preservatives/Process Fluids
Compatibility Tests for Polymeric Materials
Remaining Oil Percentage, or Thickener/Oil Ratio
ROF/ROF+
R2F and FE8 Comparison
ASTM D 3527 Life Performance of Wheel Bearing Grease
ASTM D 5483 Oxidation Induction Time of Lubricating Greases by Pressure Differential Scanning Calometry
Linear Sweep Voltammmetry
Some Qualification Criteria for Grease Selection
Low Temperature Limit
Low Temperature Performance Limit
High Temperature Performance Limit
High Temperature Limit
Minimum Speed
Maximum Speed
PumpabilityLubrication Systems
Single Point Lubrication Methods
Centralized Grease Lubrication Systems
Pumps
Shovel Pump for Pumping High Viscous Grease
Method to Create a Positive Head Pressure by Using a Follower Plate
Valves
Distributors
Single-Line Centralized Lubrication Systems
Single-Line System and Venting
Prelubrication Distributors
Relubrication Distributors
Strengths and Weaknesses of Single-Line Systems
Dual-Line Lubrication SystemsDescriptionStrengths and Weaknesses of the Dual-Line System
Progressive Lubrication SystemsDescriptionStrengths and Weaknesses of Progressive Systems
Multi-Line Lubrication System
Cyclic Grease Flow
Requirements of the Grease
Grease Pumpability
Venting Pressure for Single-Line Systems
Oil Separation/Bleeding
Cleanliness
Compressibility
Homogeneity
Additives
Compatibility
Delivery Resistance or Pressure Losses
Grease Pumpability Tests
Flow Ability
Delivery Test
A Characteristics of Paraffinic Hydrocarbons