Hydrostatic Transmissions and Actuators (eBook)

Gustavo Koury Costa graduated in 1992 with a bachelor degree in Mechanical Engineering and has been teaching Fluid Power for 19 years at his current institution. He also holds a Doctorate degree in Computational Fluid Dynamics, having spent one year as a Postdoctoral Fellow at the University of Manitoba Fluid Power and Tele-Robotics Research Laboratory. Nariman Sepehri is a professor in Mechanical Engineering. He holds five patents and has published over 100 journal articles on various aspects of fluid power, including systems, manipulation, diagnosis and control. His current research focuses on self-healing, energy-efficient and reliable fluid power systems with applications to aircraft, hydraulic tele-manipulators and off-highway equipment. He is a Fellow and has served as Chair of the Fluid Power Systems and Technology Division of the American Society of Mechanical Engineers (ASME). He has served on editorial boards of eight journals including the International Journal of Fluid Power.

Preface xiii

Acknowledgements xvii

About the Companion Website xix

1 Introduction to Power Transmission 1

1.1 Transmission Ratio 1

1.2 Mechanical Transmissions 4

1.3 Hydraulic Transmissions 15

1.4 Hydrostatic Transmissions 19

1.5 Hydromechanical Power-Split Transmissions 40

1.6 Mechanical and Hydrostatic Actuators 51

Exercises 56

References 57

2 Fundamentals of Fluid Flows in Hydrostatic Transmissions 59

2.1 Fluid Properties 59

Exercises 94

References 96

3 Hydrostatic Pumps and Motors 98

3.1 Hydrostatic and Hydrodynamic Pumps and Motors 98

3.2 Hydrostatic Machine Output 102

3.3 Hydrostatic Pump and Motor Types 117

3.4 Energy Losses at Steady-State Operation 135

3.5 Modelling Pump and Motor Efficiencies 141

Exercises 162

References 164

4 Basic Hydrostatic Transmission Design 166

4.1 General Considerations 166

4.2 Hydrostatic Transmission Efficiency 168

4.3 Transmission Output 183

4.4 Steady-State Design Applications 184

4.5 External Leakages and Charge Circuit 198

4.6 Heat Losses and Cooling 201

Exercises 204

References 205

5 Dynamic Analysis of Hydrostatic Transmissions 207

5.1 Introduction 207

5.2 Modelling and Simulation 219

Exercises 240

References 241

6 Hydrostatic Actuators 243

6.1 Introductory Concepts 243

6.2 Hydrostatic Actuator Circuits 247

6.3 Common Pressure Rail and Hydraulic Transformers 275

Exercises 281

References 282

7 Dynamic Analysis of Hydrostatic Actuators 283

7.1 Introduction 283

7.2 Mathematical Model 284

7.3 Case Study 298

Exercises 304

References 306

8 Practical Applications 307

8.1 Infinitely Variable Transmissions in Vehicles 307

8.2 Heavy Mobile Equipment 310

8.3 Hybrid Vehicles 313

8.4 Wind Turbines 323

8.5 Wave Energy Extraction 331

8.6 Aeronautical Applications 333

References 336

Appendix A Hydraulic Symbols 339

Appendix B Mathematics Review 345

B.1 The Nabla Operator ( nabla) 345

B.2 Ordinary Differential Equations (ODEs) 346

References 360

Appendix C Fluid Dynamic Equations 361

C.1 Introduction 361

C.2 Fluid Stresses and Distortion Rates 363

C.3 Differential Fluid Dynamics Equations 365

C.4 Control Volume Analysis 371

References 378

Index 379