Fluid Power Engineering

Contents......Page 10
Preface......Page 20
1.1 Introduction......Page 24
1.2.1 Mechanical Power Systems......Page 25
1.2.2 Electrical Power Systems......Page 26
1.2.3 Pneumatic Power Systems......Page 27
1.2.4 Hydrodynamic Power Systems......Page 28
1.2.5 Hydrostatic Power Systems......Page 29
1.3 Basic Hydraulic Power Systems......Page 31
1.4 The Advantages and Disadvantages of Hydraulic Systems......Page 32
1.5 Comparing Power Systems......Page 33
1.6 Exercises......Page 34
1.7 Nomenclature......Page 36
2.1 Introduction......Page 38
2.2.1 Viscosity......Page 39
2.2.2 Oil Density......Page 48
2.2.3 Oil Compressibility......Page 53
2.2.4 Thermal Expansion......Page 60
2.2.5 Vapor Pressure......Page 61
2.2.10 Foaming......Page 62
2.2.11 Cleanliness......Page 63
2.2.14 Toxicity......Page 68
2.3.1 Typically Used Hydraulic Fluids......Page 69
2.3.3 Fire-Resistant Fluids......Page 70
2.5 Requirements Imposed on the Hydraulic Liquid......Page 72
2.6 Exercises......Page 73
2.7 Nomenclature......Page 76
Appendix 2A: Transfer Functions......Page 77
Appendix 2B: Laminar Flow in Pipes......Page 78
3.2 Hydraulic Tubing......Page 82
3.3 Hoses......Page 87
3.4.1 Minor Losses......Page 91
3.4.2 Friction Losses......Page 93
3.5 Modeling of Hydraulic Transmission Lines......Page 95
3.6 Exercises......Page 99
Properties of the Laplace Transform......Page 100
Laplace Transform Tables......Page 101
The Single-Lump Model......Page 102
The Two-Lump Model......Page 103
The Four-Lump Model......Page 104
Case Study......Page 105
4.1 Introduction......Page 112
4.2 Ideal Pump Analysis......Page 114
4.3 Real Pump Analysis......Page 117
4.4 Cavitation in Displacement Pumps......Page 120
4.5 Pulsation of Flow of Displacement Pumps......Page 121
4.6.1 Bent Axis Axial Piston Pumps......Page 123
4.6.2 Swash Plate Pumps with Axial Pistons......Page 126
4.6.3 Swash Plate Pumps with Inclined Pistons......Page 128
4.6.5 Radial Piston Pumps with Eccentric Cam Ring......Page 129
4.6.6 Radial Piston Pumps with Eccentric Shafts......Page 131
4.6.8 External Gear Pumps......Page 132
4.6.9 Internal Gear Pumps......Page 137
4.6.10 Gerotor Pumps......Page 138
4.6.12 Vane Pumps......Page 140
4.7.1 General......Page 145
4.7.2 Pressure-Compensated Vane Pumps......Page 146
4.7.3 Bent Axis Axial Piston Pumps with Power Control......Page 148
4.8 Rotodynamic Pumps......Page 151
4.9 Pump Summary......Page 153
4.11 Exercises......Page 157
4.12 Nomenclature......Page 160
5.1 Introduction......Page 162
5.2.1 Direct-Operated Relief Valves......Page 164
5.2.2 Pilot-Operated Relief Valves......Page 167
5.2.3 Pressure-Reducing Valves......Page 170
5.2.4 Sequence Valves......Page 175
5.2.5 Accumulator Charging Valve......Page 178
5.3.2 Poppet-Type DCVs......Page 180
5.3.3 Spool-Type DCVs......Page 181
5.3.4 Control of the Directional Control Valves......Page 184
5.3.5 Flow Characteristics of Spool Valves......Page 190
5.3.6 Pressure and Power Losses in the Spool Valves......Page 192
5.3.7 Flow Forces Acting on the Spool......Page 193
5.3.8 Direct-Operated Directional Control Valves......Page 195
5.3.9 Pilot-Operated Directional Control Valves......Page 196
5.4.1 Spring-Loaded Direct-Operated Check Valves......Page 198
5.4.3 Pilot-Operated Check Valves Without External Drain Ports......Page 199
5.4.5 Double Pilot-Operated Check Valves......Page 201
5.5 Flow Control Valves......Page 202
5.5.2 Sharp-Edged Throttle Valves......Page 203
5.5.3 Series Pressure-Compensated Flow Control Valves......Page 204
5.5.4 Parallel Pressure-Compensated Flow Control Valves—Three-Way FCVs......Page 207
5.5.5 Flow Dividers......Page 208
5.6 Exercises......Page 211
5.7 Nomenclature......Page 213
Conical Poppet Valves......Page 214
Cylindrical Poppets with Conical Seats......Page 215
Spherical Poppet Valves......Page 216
Circular Throttling Area......Page 219
Triangular Throttling Area......Page 220
Appendix 5B: Modeling and Simulation of a Direct-Operated Relief Valve......Page 221
Mathematical Modeling......Page 222
Static Characteristics......Page 224
Transient Response......Page 225
Nomenclature......Page 227
6.1 Introduction......Page 230
6.2.1 Classification and Operation......Page 231
6.2.2 The Volumetric Capacity of Accumulators......Page 233
6.2.3 The Construction and Operation of Accumulators......Page 234
6.2.4 Applications of Hydraulic Accumulators......Page 239
6.3 Hydraulic Filters......Page 260
6.4.1 Piston-Type Pressure Switches......Page 261
6.4.2 Bourdon Tube Pressure Switches......Page 262
6.4.3 Pressure Gauge Isolators......Page 263
6.5 Exercises......Page 264
Appendix 6A: Smoothing Pressure Pulsations by Accumulators......Page 266
Appendix 6B: Absorption of Hydraulic Shocks by Accumulators......Page 269
Nomenclature and Abbreviations......Page 272
7.2 Hydraulic Cylinders......Page 274
7.2.1 The Construction of Hydraulic Cylinders......Page 275
7.2.2 Cylinder Cushioning......Page 276
7.2.4 Cylinder Buckling......Page 279
7.2.6 Classifications of Hydraulic Cylinders......Page 281
7.2.7 Cylinder Mounting......Page 284
7.2.8 Cylinder Calibers......Page 285
7.3.2 Parallel Piston Rotary Actuator......Page 287
7.4.1 Introduction......Page 288
7.4.2 Bent-Axis Axial Piston Motors......Page 289
7.4.3 Swash Plate Axial Piston Motors......Page 290
7.4.4 Vane Motors......Page 291
7.5 Exercises......Page 292
7.6 Nomenclature......Page 294
Appendix 7A: Case Studies: Hydraulic Circuits......Page 295
8.1 Construction and Operation......Page 304
8.2.1 The Steering Systems of Mobile Equipment......Page 306
8.2.2 Applications in Machine Tools......Page 307
8.2.3 Applications in Displacement Pump Controls......Page 308
8.3 The Mathematical Model of HSA......Page 309
8.4.2 Deducing the HSA Transfer Function Analytically......Page 312
8.5.1 Flow Characteristics......Page 315
8.5.2 Power Characteristics......Page 318
8.6 Exercises......Page 319
8.7 Nomenclature......Page 320
Appendix 8A: Modeling and Simulation of a Hydraulic Servo Actuator......Page 321
A Mathematical Model of the HSA......Page 322
Simulation of the HSA......Page 323
Nomenclature......Page 326
9.1 Introduction......Page 328
9.3 Electromagnetic Motors......Page 329
9.4.1 Single-Stage Servovalves......Page 334
9.4.2 Two-Stage Electrohydraulic Servovalves......Page 336
9.5 Servovalves Incorporating Jet Pipe Amplifiers......Page 347
9.6 Servovalves Incorporating Jet Deflector Amplifiers......Page 350
9.7 Jet Pipe Amplifiers Versus Nozzle Flapper Amplifiers......Page 353
9.8 Exercises......Page 354
10.2.1 Introducing Magnetic Circuits......Page 356
10.2.2 Magnetic Circuit of an Electromagnetic Torque Motor......Page 359
10.2.3 Analysis of Torque Motors......Page 360
10.3 Flapper Valves......Page 363
10.4 Modeling of an Electrohydraulic Servo Actuator......Page 365
10.5 Exercises......Page 370
10.6 Nomenclature......Page 371
Appendix 10A: Modeling and Simulation of an EHSA......Page 372
Numerical Values of the Studied System......Page 373
Torque Motors......Page 374
Single-Stage Electrohydraulic Servovalves......Page 375
Two-Stage Electrohydraulic Servovalves......Page 377
Electrohydraulic Servo Actuators (EHSAs)......Page 381
Appendix 10B: Design of P, PI, and PID Controllers......Page 384
11.2.1 Effects of Air Compressibility......Page 390
11.2.4 Other Peculiarities of Pneumatic Systems......Page 395
11.3.2 Basic Disadvantages of Pneumatic Systems......Page 396
11.4.2 Air Compressors......Page 397
11.4.4 Air Filters......Page 401
11.4.6 Pneumatic Control Valves......Page 402
11.5.3 Bidirectional Speed Control of a Single-Acting Cylinder......Page 408
11.5.4 OR Control of a Single-Acting Cylinder......Page 409
11.5.7 Logic NOT Control......Page 410
11.5.9 Bidirectional Speed Control of a Double-Acting Cylinder......Page 411
11.5.10 Unidirectional and Quick Return Control of a Double-Acting Cylinder......Page 412
11.5.11 Dual Pressure Control of a Double-Acting Cylinder......Page 414
11.5.15 Basic Positional Control of a Double-Acting Cylinder......Page 415
11.5.17 Electro-Pneumatic Logic OR......Page 419
11.5.18 Electro-Pneumatic Logic MEMORY......Page 420
11.6 Exercises......Page 421
11.7 Nomenclature......Page 422
References......Page 424
Index......Page 428
A......Page 430
C......Page 431
D......Page 432
E......Page 433
F......Page 434
G......Page 435
H......Page 436
K......Page 438
P......Page 439
R......Page 441
T......Page 442
Z......Page 443