Page 9 - Tribology in Machine Design

viii Contents

4.15.11. Lubrication of seals 172
References 173
5. Sliding-element bearings 174
5.1. Derivation of the Reynolds equation 174
5.2. Hydrostatic bearings 178
5.3. Squeeze-film lubrication bearings 181
5.4. Thrust bearings 183
5.4.1. Flat pivot 184
5.4.2. The effect of the pressure gradient in the direction
of motion 186
5.4.3. Equilibrium conditions 188
5.4.4. The coefficient of friction and critical slope 188
5.5. Journal bearings 189
5.5.1. Geometrical configuration and pressure
generation 189
5.5.2. Mechanism of load transmission 192
5.5.3. Thermoflow considerations 194
5.5.4. Design for load-bearing capacity 196
5.5.5. Unconventional cases of loading 197
5.5.6. Numerical example 199
5.5.7. Short bearing theory - CAD approach 201
5.6. Journal bearings for specialized applications 204
5.6.1. Journal bearings with fixed non-preloaded pads 205
5.6.2. Journal bearings with fixed preloaded pads 205
5.6.3. Journal bearings with special geometric features 207
5.6.4. Journal bearings with movable pads 207
5.7. Gas bearings 210
5.8. Dynamically loaded journal bearings 212
5.8.1. Connecting-rod big-end bearing 213
5.8.2. Loads acting on main crankshaft bearing 213
5.8.3. Minimum oil film thickness 214
5.9. Modern developments in journal bearing design 217
5.9.1. Bearing fit 218
5.9.2. Grooving 219
5.9.3. Clearance 219
5.9.4. Bearing materials 220
5.10. Selection and design of thrust bearings 221
5.10.1. Tilting-pad bearing characteristics 223
5.10.2. Design features of hydrostatic thrust bearings 225
5.11. Self-lubricating bearings 226
5.11.1. Classification of self-lubricating bearings 226
5.11.2. Design considerations . 228
References 230
6. Friction, lubrication and wear in higher kinematic pairs 232
6.1. Introduction 232
6.2. Loads acting on contact area 233