Preface ........................................................ xi
Usual Meaning of Symbols ..................................... xiii
Chapter 1: Application .......................................... 1
1.1 Introduction ............................................... 1
1.2 What are Hydrostatic, Hybrid, and Aerostatic Bearings? ..... 2
1.3 When are Hydrostatic, Hybrid, and Aerostatic Bearings
Employed? .................................................. 7
1.4 Bearing Selection .......................................... 9
1.5 Bearing Categories ........................................ 12
1.6 Commercial Applications ................................... 16
1.7 Materials and Manufacture ................................. 18
1.8 Aerostatic Bearings ....................................... 22
1.9 How to Read and Use the Book .............................. 23
References ..................................................... 23
Chapter 2: Basic Flow Theory ................................... 25
2.1 Introduction .............................................. 25
2.2 Viscosity ................................................. 25
2.3 Density and Consistent Units .............................. 27
2.4 Compressibility ........................................... 27
2.5 Viscous Flow Between Parallel Plates ...................... 28
2.6 Combined Pressure- and Velocity-Induced Viscous Flow
in a Two-Dimensional Npnparallel Film ..................... 32
2.7 Flow Through Restrictors .................................. 33
2.8 Recess Pressure and Pressure Ratio ........................ 37
2.9 Bearing Load .............................................. 39
2.10 Use of Normalized Data .................................... 42
2.11 Aerostatic Bearings—Summary of Relationships .............. 44
References ..................................................... 48
Further Reading ................................................ 48
Chapter 3: Power, Temperature Rise, and Shape Optimization ..... 49
Summary of Key Design Formulae ................................. 49
3.1 Introduction .............................................. 49
3.2 Pumping Power Hp .......................................... 49
3.3 Friction Power Hf ......................................... 50
3.4 Power Ration K ............................................ 50
3.5 Temperature Rise ΔT........................................ 51
3.6 Minimum Power as an Optimization Criterion ................ 53
3.7 Minimum Power for Low-Speed Bearings (K = 0) .............. 53
3.8 Minimum Power for High-Speed Recessed Bearings ............ 54
3.9 Speed Parameter Sf, and Optimum Value Sho ................. 57
3.10 Optimization of Plain Nonrecessed Hybrid Bearings ......... 63
References ..................................................... 63
Chapter 4: Pads: Area and Flow Shape Factors (A and B) ......... 65
Summary of Key Design Formulae ................................. 65
4.1 Pad Shapes and Shape Factors .............................. 65
4.2 Virtual Recesses and Dispersion Losses .................... 65
4.3 Circular Pads ............................................. 70
4.4 Square Pad Data ........................................... 71
4.5 Rectangular Pad Data ...................................... 72
4.6 Annular Recess Circular Pad Data .......................... 72
4.7 Conical Pad Data .......................................... 73
4.8 Spherical Pad Data ........................................ 75
4.9 Multi-Recess Circular Pad Data ............................ 76
4.10 Multi-Recess Rectangular Pad Data ......................... 77
4.11 Data for Rectangular Pad with Radiussed Recess Corners .... 78
4.12 Data for Any Shape with Thin Constant Land Width .......... 79
4.13 Annular Multi-Recess Pad Data ............................. 79
Chapter 5: Flow Control and Restrictors ........................ 83
Summary of Key Design Formulae ................................. 83
5.1 Introduction .............................................. 83
5.2 Bearing Film Stiffness .................................... 84
5.3 Hydrostatic Circuit Design and Sealing .................... 85
5.4 Load and Stiffness of Capillary-Controlled Pads ........... 86
5.5 Flow Control Mechanisms ................................... 90
5.6 General Stiffness Laws for Hydrostatic and Aerostatic
Bearing Pads ............................................. 102
5.7 Aerostatic Bearings and Flow Control ..................... 104
References .................................................... 109
Appendix: Tabular Design Procedures for Restrictors and
Worked Examples ............................................... 110
Chapter 6: Basis of Design Procedures ......................... 115
6.1 Introduction ............................................. 115
6.2 An Acceptable Range for Design Pressure Ratio ............ 115
6.3 Zero- and Low-Speed Hydrostatic Bearings ................. 116
6.4 Zero- and Low-Speed Aerostatic Bearings .................. 117
6.5 Optional Size Limits and Tolerances for Film Thickness ... 118
6.6 High-Speed Bearings ...................................... 119
6.7 Specification for ISO Limits and Fits .................... 122
6.8 Tolerance Grades for Hydrostatic and Aerostatic
Bearings ................................................. 122
References .................................................... 124
Chapter 7: Plane Hydrostatic and Aerostatic Bearings .......... 725
Summary of Key Design Formulae ................................ 125
7.1 Use of the Design Charts ................................. 125
7.2 Choice of Land Width ..................................... 125
7.3 Flow Variation with Film Thickness ....................... 126
7.4 Load Variation with Film Thickness ....................... 126
7.5 Stiffness Variation with Film Thickness .................. 127
7.6 Single-Pad Bearings ...................................... 127
7.7 Equal Opposed-Pad Bearings ............................... 138
7.8 Unequal Opposed-Pad Bearings ............................. 146
7.9 Complex Arrangements of Pads (Capillary Controlled) ...... 147
Appendix: Tabular Design Procedures ........................... 154
Chapter 8: Partial Journal Bearings ........................... 167
Summary of Key Design Formulae ................................ 167
8.1 Recessed Partial Journal Bearings ........................ 167
8.2 Partial Journal Bearings with a High-Pressure Supply
Groove ................................................... 174
Reference ..................................................... 178
Chapter 9: Recessed Hydrostatic Journal Bearings .............. 179
Summary of Key Design Formulae ................................ 179
9.1 Introduction ............................................. 179
9.2 Row ...................................................... 181
9.3 Load ..................................................... 186
9.4 Power, Power Ratio, and Temperature Rise ................. 191
9.5 Land-Width Ratios and Concentric Pressure Ratio .......... 192
9.6 Selection of Tolerances for Bearing Film Clearance ....... 192
9.7 Selection of Supply Pressure, Viscosity, and Clearance ... 193
9.8 Bearing Film Stiffness ................................... 197
References .................................................... 202
Appendix 1: Derivation of Journal Bearing Stiffness by an
Approximate Analytical Method ..................... 202
Appendix 2: Tabular Design Procedure .......................... 204
Chapter 10: Plain Journal Bearings ............................ 207
Summary of Key Design Formulae ................................ 207
Part A. Hydrostatic/Hybrid Plain Journal Bearings ............. 207
10.1 Introduction ............................................ 207
10.2 Selection of Bearing Configuration ...................... 208
10.3 Power Ratio, К .......................................... 210
10.4 Concentric Hydrostatic Pressure Ratio, β ................ 210
10.5 Bearing Clearance and Clearance Limits .................. 210
10.6 Hydrostatic Load Support ................................ 213
10.7 Hybrid Slot-Entry Bearings .............................. 215
10.8 Hybrid Hole-Entry Bearings .............................. 218
10.9 Size of Slot and Hole-Entry Ports ....................... 219
10.10 Summary of Hydrostatic and Hybrid Load Support .......... 220
10.11 Concentric Hydrostatic/Hybrid Flow ...................... 220
10.12 Power and Temperature Rise .............................. 222
Part B. Aerostatic Plain Journal Bearings ..................... 225
10.13 Introduction to Aerostatic Journal Bearings ............. 225
10.14 Concentric Aerostatic Pressure Ratio, Kgo ............... 225
10.15 Aerostatic Clearance and Clearance Limits ............... 226
10.16 Aerostatic Load Support ................................. 226
10.17 Concentric Aerostatic Flow .............................. 227
10.18 Hybrid Aerostatic Journal Bearings ...................... 229
10.19 Materials and Surface Texture for Journal Bearings ...... 231
References .................................................... 231
Appendix: Tabular Design Procedures ........................... 232
Chapter 11: The Yates Bearing ................................. 239
Summary of Key Design Formulae ................................ 239
11.1 Introduction ............................................ 239
11.2 Principle of Operation .................................. 241
11.3 Basic Parameters for the Yates Bearing .................. 242
11.4 Hydrostatic Design Procedure ............................ 250
11.5 Aerostatic Yates Bearings ............................... 255
11.6 Aerostatic Design Procedure ............................. 256
References .................................................... 258
Chapter 12: Conical Journal Bearings .......................... 259
Summary of Key Design Formulae ................................ 259
12.1 Application .............................................. 259
12.2 Basic Parameters ........................................ 262
12.3 Single-Cone Bearings .................................... 264
12.4 Complementary-Cone Spindle Bearings ..................... 265
12.5 High-Speed Design ....................................... 269
12.6 Design Procedure for a Complementary-Cone Hydrostatic
Bearing ................................................. 269
12.7 Design Procedure for a Complementary-Cone Aerostatic
Bearing ................................................. 272
References .................................................... 274
Chapter 13: Spherical Bearings ................................ 275
Summary of Key Design Formulae ................................ 275
13.1 Application ............................................. 275
13.2 Basic Parameters ........................................ 277
13.3 Central-Recess Spherical Bearing ........................ 279
13.4 Annular-Recess Spherical Bearing ........................ 282
13.5 Single Multi-Recess Spherical Bearings .................. 283
13.6 Opposed Multi-Recess Spherical Bearings ................. 283
Reference ..................................................... 287
Chapter 14: Dynamics .......................................... 289
Summary of Key Design Formulae ................................ 289
14.1 Introduction ............................................ 289
14.2 Static Loading .......................................... 290
14.3 Dynamic Loading ......................................... 291
14.4 Squeeze Film Damping .................................... 292
14.5 Compressibility in Hydrostatic and Aerostatic Bearings .. 293
14.6 Dynamic Model of a Thrust Pad ........................... 294
14.7 Hydrostatic Thrust Pad with Thin Lands .................. 297
14.8 Journal Bearings: Equations of Motion ................... 301
14.9 Journal Bearings in the Concentric Condition ............ 303
14.10 Eccentric Journal Bearings .............................. 311
References .................................................... 313
Chapter 15: Experimental Methods and Testing .................. 315
15.1 Introduction ............................................ 315
15.2 Hat-Pad Rig ............................................. 316
15.3 Cylindrical Journal Bearing Rig ......................... 318
15.4 Publications on Experimental Behavior ................... 322
References .................................................... 322
Index ......................................................... 325
|
