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List of Contributors xv Preface xvii Acknowledgements xxi
PART I OVERTURE 1 1 Wear in the Heavy Duty Engine 3
1.1 Introduction 3
1.2 Engine Life 3
1.3 Wear in Engines 4
1.3.1 Natural Aging 4
1.4 General Wear Model 5
1.5 Wear of Engine Bearings 5
1.6 Wear of Piston Rings and Liners 6
1.7 Wear of Valves and Valve Guides 6
1.8 Reduction in Wear Life of Critical Parts Due to Contaminants in Oil 6
1.8.1 Oil Analysis 7
1.9 Oils for New Generation Engines with Longer Drain Intervals 8
1.9.1 Engine Oil Developments and Trends 8
1.9.2 Shift in Engine Oil Technology 9
1.10 Filters 9
1.10.1 Air Filter 9
1.10.2 Oil Filter 10
1.10.3 Water Filter 10
1.10.4 Fuel Filter 10
1.11 Types of Wear of Critical Parts in a Highly Loaded Diesel Engine 10
1.11.1 Adhesive Wear 10
1.11.2 Abrasive Wear 11
1.11.3 Fretting Wear 11
1.11.4 Corrosive Wear 11 References 11 2 Engine Size and Life 13
2.1 Introduction 13
2.2 Engine Life 13
2.3 Factors on Which Life is Dependent 14
2.4 Friction Force and Power 14
2.4.1 Mechanical Efficiency 14
2.4.2 Friction 15
2.5 Similarity Studies 15
2.5.1 Characteristic Size of an Engine 15
2.5.2 Velocity 16
2.5.3 Oil Film Thickness 17
2.5.4 Velocity Gradient 18
2.5.5 Friction Force or Power 18
2.5.6 Indicated Power and Efficiency 18
2.6 Archard''s Law of Wear 20
2.7 Wear Life of Engines 20
2.7.1 Wear Life 20
2.7.2 Nondimensional Wear Depth Achieved During Lifetime 21
2.8 Summary 23 Appendix
2.A Engine Parameters, Mechanical Efficiency and Life 25 Appendix
2.B Hardness and Fatigue Limits of Different Copper-Lead-Tin (Cu-Pb-Sn) Bearings 26 Appendix
2.C Hardness and Fatigue Limits of Different Aluminium-Tin (Al-Sn) Bearings 28 References 29
PART II VALVE TRAIN COMPONENTS 31 3 Inlet Valve Seat Wear in High bmep Diesel Engines 33
3.1 Introduction 33
3.2 Valve Seat Wear 34
3.2.1 Design Aspects to Reduce Valve Seat Wear Life 34
3.3 Shear Strain and Wear due to Relative Displacement 35
3.4 Wear Model 35
3.4.1 Wear Rate 36
3.5 Finite Element Analysis 37
3.6 Experiments, Results and Discussions 38
3.6.1 Valve and Seat Insert of Existing Design 39
3.6.2 Improved Valve and Seat Insert 39
3.7 Summary 45
3.8 Design Rule for Inlet Valve Seat Wear in High bmep Engines 45 References 45 4 Wear of the Cam Follower and Rocker Toe 47
4.1 Introduction 47
4.2 Wear of Cam Follower Surfaces 48
4.2.1 Wear Mechanism of the Cam Follower 48
4.3 Typical Modes of Wear 50
4.4 Experiments on Cam Follower Wear 51
4.4.1 Follower Measurement 51
4.5 Dynamics of the Valve Train System of the Pushrod Type 52
4.5.1 Elastohydrodynamic and Transition of Boundary Lubrication 52
4.5.2 Cam and Follower Dynamics 53
4.6 Wear Model 55
4.6.1 Wear Coefficient 55
4.6.2 Valve Train Dynamics and Stress on the Follower 55
4.6.3 Wear Depth 61
4.7 Parametric Study 64
4.7.1 Engine Speed 64
4.7.2 Oil Film Thickness 64
4.8 Wear of the Cast Iron Rocker Toe 64
4.9 Summary 66 References 66
PART III LINER, PISTON AND PISTON RINGS 69 5 Liner Wear: Wear of Roughness Peaks in Sparse Contact 71
5.1 Introduction 71
5.2 Surface Texture of Liners and Rings 72
5.2.1 Surface Finish 72
5.2.2 Honing of Liners 72
5.2.3 Surface Finish Parameters 72
5.2.4 Bearing Area Curve 74
5.2.5 Representation of Bearing Area Curve of Normally Honed Surface or Surfaces with Peaked Roughness 75
5.3 Wear of Liner Surfaces 76
5.3.1 Asperities 76
5.3.2 Radius of the Asperity in the Transverse Direction 76
5.3.3 Radius in the Longitudinal Direction 77
5.3.4 Sparse Contact 77
5.3.5 Contact Pressures 79
5.3.6 Friction 79
5.3.7 Approach 80
5.3.8 Detachment of Asperities 80
5.4 Wear Model 81
5.4.1 Normally Honed Liner with Peaked Roughness 81
5.4.2 Normal Surface Roughness 81
5.4.3 Fatigue Loading of Asperities 81
5.4.4 Wear Rate 82
5.4.5 Plateau Honed and Other Liners not Normally Honed 83
5.5 Liner Wear Model for Wear of Roughness Peaks in Sparse Contact 85
5.5.1 Parametric Studies 86
5.5.2 Comparison with Archard''s Model 88
5.6 Discussions on Wear of Liner Roughness Peaks due to Sparse Contact 89
5.7 Summary 92 Appendix
5.A Sample Calculation of the Wear of a Rough Plateau Honed Liner 93 References 93 6 Generalized Boundary Conditions for Designing Diesel Pistons 95
6.1 Introduction 95
6.2 Temperature Distribution and Form of the Piston 96
6.2.1 Top Land 96
6.2.2 Skirt 96
6.3 Experimental Mapping of Temperature Field in the Piston 97
6.4 Heat Transfer in Pistons 98
6.4.1 Metal Slab 98
6.5 Calculation of Piston Shape 98
6.5.1 Popular Methods Used Before Finite Element Analysis 99
6.5.2 Calculation by Finite Element Method 101
6.5.3 Experimental Validation 103
6.6 Summary 108 References 109 7 Bore Polishing Wear in Diesel Engine Cylinders 111
7.1 Introduction 111
7.2 Wear Phenomenon for Liner Surfaces 112
7.2.1 Bore Polishing 112
7.3 Bore Polishing Mechanism 113
7.3.1 Carbon Deposit Build Up on the Piston Top Land 113
7.3.2 Quality of Fuel and Oil 113
7.3.3 Piston Growth by Finite Element Method 113
7.3.4 Piston Secondary Movement 114
7.3.5 Simulation Program 115
7.4 Wear Model 115
7.4.1 Contact Pressures 115
7.4.2 Wear Rate 116
7.5 Calculation Methodology and Study of Bore Polishing Wear 116
7.5.1 Finite Element Analysis 116
7.5.2 Simulation 117
7.6 Case Study on Bore Polishing Wear in Diesel Engine Cylinders 118
7.6.1 Visual Observations 118
7.6.2 Liner Measurements 119
7.6.3 Results of Finite Element Analysis 119
7.6.4 Piston Motion 121
7.6.5 Wear Profile 123
7.6.6 Engine Oil Consumption 125
7.6.7 Methods Used to Reduce Liner Wear 125
7.7 Summary 127 References 127 8 Abrasive Wear of Piston Grooves in Highly Loaded Diesel Engines 129
8.1 Introduction 129
8.2 Wear Phenomenon in Piston Grooves 130
8.2.1 Abrasive Wear 130
8.2.2 Wear Mechanism 130
8.3 Wear Model 132
8.3.1 Real Contact Pressure 132
8.3.2 Approach 132
8.3.3 Wear Rate 132
8.4 Experimental Validation 134
8.4.1 Validation of the Model 134
8.4.2 Wear Measurement 135
8.5 Estimation of Wear Using Sarkar''s Model 137
8.5.1 Parametric Study 138
8.6 Summary 139 References 140 9 Abrasive Wear of Liners and Piston Rings 141
9.1 Introduction 141
9.2 Wear of Liner and Ring Surfaces 141
9.3 Design Parameters 143
9.3.1 Piston and Rings Assembly 143
9.3.2 Abrasive Wear 143
9.3.3 Sources of Abrasives 144
9.4 Study of Abrasive Wear on Off-highway Engines 144
9.4.1 Abrasive Wear of Rings 144
9.4.2 Abrasive Wear of Piston Pin and Liners 144
9.4.3 Accelerated Abrasive Wear Test on an Engine to Simulate Operation in the Field 146
9.5 Winnowing Effect 149
9.6 Scanning Electron Microscopy of Abrasive Wear 150
9.7 Critical Dosage of Sand and Life of Piston-Ring-Liner Assembly 150
9.7.1 Simulation of Engine Life 151
9.8 Summary 152 References 153 10 Corrosive Wear 155
10.1 Introduction 155
10.2 Operating Parameters 155
10.2.1 Corrosive Wear 155
10.3 Corrosive Wear Study on Off-road Application Engines 156
10.3.1 Accelerated Corrosive Wear Test 156
10.4 Wear Related to Coolants in an Engine 161
10.4.1 Under-cooling of Liners by Design 161
10.4.2 Coolant Related Wear 161
10.5 Summary 165 References 165 11 Tribological Tests to Simulate Wear on Piston Rings 167
11.1 Introduction 167
11.2 Friction and Wear Tests 168
11.2.1 Testing Friction and Wear of the Tribo-System Piston Ring and Cylinder Liner Outside of Engines 168
11.3 Test Procedures Assigned to the High Frequency, Linear Oscillating Test Machine 170
11.4 Load, Friction and Wear Tests 172
11.4.1 EP Test 172
11.4.2 Scuffing Test 172
11.4.3 Reagents and Materials 172
11.5 Test Results 175
11.5.1 Selection of Coatings for Piston Rings 175
11.5.2 Scuffing Tribological Test 178
11.5.3 Hot Endurance Test 179
11.6 Selection of Lubricants 184
11.7 High Performance Bio-lubricants and Tribo-reactive Materials for Clean Automotive Applications 185
11.7.1 Synthetic Esters 185
11.7.2 Polyalkyleneglycols 185
11.8 Tribo-Active Materials 190
11.8.1 Thematic ''Piston Rings'' 190
11.9 EP Tribological Tests 192
11.9.1 Piston Ring Cylinder Liner Simulation 192 Acknowledgements 194 References 194
PART IV ENGINE BEARINGS 197 12 Friction and Wear in Engine Bearings 199
12.1 Introduction 199
12.2 Engine Bearing Materials 202
12.2.1 Babbitt or White Metal 202
12.2.2 Copper-Lead Alloys 203
12.2.3 Aluminium-based Materials 204
12.3 Functions of Engine Bearing Layers 205
12.4 Types of Overlays/Coatings in Engine Bearings 206
12.4.1 Lead-based Overlays 208
12.4.2 Tin-based Overlays 208
12.4.3 Sputter Bea