HYDRAULIC AND PNEUMATIC ENGINEERING
CONTENTS INTRODUCTION TO HYDRAULIC POWER SYSTEMS 1 1 INTRODUCTION 1 2 THE CLASSI? CATION OF POWER SYSTEMS 1 2 1 MECHANICAL POWER SYSTEMS 1 2 2 ELECTRICAL POWER SYSTEMS 1 2 3 PNEUMATIC POWER SYSTEMS 1 2 4 HYDRODYNAMIC POWER SYSTEMS 1 2 5 HYDROSTATIC POWER SYSTEMS 1 3 BASIC HYDRAULIC POWER SYSTEMS 1 4 THE ADVANTAGES AND DISADVANTAGES OF HYDRAULIC SYSTEMS 1 5 COMPARING POWER SYSTEMS 1 6 EXERCISES 1 7 NOMENCLATURE HYDRAULIC OILS AND THEORETICAL BACKGROUND 2 1 INTRODUCTION 2 2 BASIC PROPERTIES OF HYDRAULIC OILS 2 2 1 VISCOSITY 2 2 2 OIL DENSITY 2 2 3 OIL COMPRESSIBILITY 2 2 4 THERMAL EXPANSION 2 2 5 VAPOR PRESSURE 2 2 6 LUBRICATION AND ANTI-WEAR CHARACTERISTICS 2 2 7 COMPATIBILITY 2 2 8 CHEMICAL STABILITY 2 2 9 OXIDATION STABILITY 2 2 10 FOAMING 2 2 11 CLEANLINESS 2 2 12 THERMAL PROPERTIES 2 2 13 ACIDITY 2 2 14 TOXICITY 2 2 15 ENVIRONMENTALLY ACCEPTABLE HYDRAULIC OILS 2 3 CLASSI? CATION OF HYDRAULIC FLUIDS 2 3 1 TYPICALLY USED HYDRAULIC FLUIDS 2 3 2 MINERAL OILS 2 3 3 FIRE-RESISTANT FLUIDS 2 4 ADDITIVES 2 5 REQUIREMENTS IMPOSED ON THE HYDRAULIC LIQUID 2 6 EXERCISES 2 7 NOMENCLATURE APPENDIX 2A TRANSFER FUNCTIONS APPENDIX 2B LAMINAR FLOW IN PIPES HYDRAULIC TRANSMISSION LINES 3 1 INTRODUCTION 3 2 HYDRAULIC TUBING 3 3 HOSES 3 4 PRESSURE AND POWER LOSSES IN HYDRAULIC CONDUITS 3 4 1 MINOR LOSSES 3 4 2 FRICTION LOSSES 3 5 MODELING OF HYDRAULIC TRANSMISSION LINES 3 6 EXERCISES 3 7 NOMENCLATURE APPENDIX 3A THE LAPLACE TRANSFORM THE DIRECT LAPLACE TRANSFORM THE INVERSE LAPLACE TRANSFORM PROPERTIES OF THE LAPLACE TRANSFORM LAPLACE TRANSFORM TABLES APPENDIX 3B MODELING AND SIMULATION OF HYDRAULIC TRANSMISSION LINES THE SINGLE-LUMP MODEL THE TWO-LUMP MODEL THE THREE-LUMP MODEL THE FOUR-LUMP MODEL HIGHER-ORDER MODELS CASE STUDY HYDRAULIC PUMPS 4 1 INTRODUCTION 4 2 IDEAL PUMP ANALYSIS 4 3 REAL PUMP ANALYSIS 4 4 CAVITATION IN DISPLACEMENT PUMPS 4 5 PULSATION OF FLOW OF DISPLACEMENT PUMPS 4 6 CLASSI? CATION OF PUMPS 4 6 1 BENT AXIS AXIAL PISTON PUMPS 4 6 2 SWASH PLATE PUMPS WITH AXIAL PISTONS 4 6 3 SWASH PLATE PUMPS WITH INCLINED PISTONS 4 6 4 AXIAL PISTON PUMPS WITH ROTATING SWASH PLATE-WOBBLE PLATE 4 6 5 RADIAL PISTON PUMPS WITH ECCENTRIC CAM RING 4 6 6 RADIAL PISTON PUMPS WITH ECCENTRIC SHAFTS 4 6 7 RADIAL PISTON PUMPS OF CRANK TYPE 4 6 8 EXTERNAL GEAR PUMPS 4 6 9 INTERNAL GEAR PUMPS 4 6 10 GEROTOR PUMPS 4 6 11 SCREW PUMPS 4 6 12 VANE PUMPS 4 7 VARIABLE DISPLACEMENT PUMPS 4 7 1 GENERAL 4 7 2 PRESSURE-COMPENSATED VANE PUMPS 4 7 3 BENT AXIS AXIAL PISTON PUMPS WITH POWER CONTROL 4 8 ROTODYNAMIC PUMPS 4 9 PUMP SUMMARY 4 10 PUMP SPECI? CATION 4 11 EXERCISES 4 12 NOMENCLATURE HYDRAULIC CONTROL VALVES 5 1 INTRODUCTION 5 2 PRESSURE-CONTROL VALVES 5 2 1 DIRECT-OPERATED RELIEF VALVES 5 2 2 PILOT-OPERATED RELIEF VALVES 5 2 3 PRESSURE-REDUCING VALVES 5 2 4 SEQUENCE VALVES 5 2 5 ACCUMULATOR CHARGING VALVE 5 3 DIRECTIONAL CONTROL VALVES 5 3 1 INTRODUCTION 5 3 2 POPPET-TYPE DCVS 5 3 3 SPOOL-TYPE DCVS 5 3 4 CONTROL OF THE DIRECTIONAL CONTROL VALVES 5 3 5 FLOW CHARACTERISTICS OF SPOOL VALVES 5 3 6 PRESSURE AND POWER LOSSES IN THE SPOOL VALVES 5 3 7 FLOW FORCES ACTING ON THE SPOOL 5 3 8 DIRECT-OPERATED DIRECTIONAL CONTROL VALVES 5 3 9 PILOT-OPERATED DIRECTIONAL CONTROL VALVES 5 4 CHECK VALVES 5 4 1 SPRING-LOADED DIRECT-OPERATED CHECK VALVES 5 4 2 DIRECT-OPERATED CHECK VALVES WITHOUT SPRINGS 5 4 3 PILOT-OPERATED CHECK VALVES WITHOUT EXTERNAL DRAIN PORTS 5 4 4 PILOT-OPERATED CHECK VALVES WITH EXTERNAL DRAIN PORTS 5 4 5 DOUBLE PILOT-OPERATED CHECK VALVES 5 4 6 MECHANICALLY PILOTED PILOT-OPERATED CHECK VALVES 5 5 FLOW CONTROL VALVES 5 5 1 THROTTLE VALVES 5 5 2 SHARP-EDGED THROTTLE VALVES 5 5 3 SERIES PRESSURE-COMPENSATED FLOW CONTROL VALVES 5 5 4 PARALLEL PRESSURE-COMPENSATED FLOW CONTROL VALVES—THREE-WAY FCVS 5 5 5 FLOW DIVIDERS 5 6 EXERCISES 5 7 NOMENCLATURE APPENDIX 5A CONTROL VALVE PRESSURES AND THROTTLE AREAS CONICAL POPPET VALVES CYLINDRICAL POPPETS WITH CONICAL SEATS SPHERICAL POPPET VALVES CIRCULAR THROTTLING AREA TRIANGULAR THROTTLING AREA APPENDIX 5B MODELING AND SIMULATION OF A DIRECT-OPERATED RELIEF VALVE CONSTRUCTION AND OPERATION OF THE VALVE MATHEMATICAL MODELING COMPUTER SIMULATION STATIC CHARACTERISTICS TRANSIENT RESPONSE NOMENCLATURE ACCESSORIES 6 1 INTRODUCTION 6 2 HYDRAULIC ACCUMULATORS 6 2 1 CLASSI? CATION AND OPERATION 6 2 2 THE VOLUMETRIC CAPACITY OF ACCUMULATORS 6 2 3 THE CONSTRUCTION AND OPERATION OF ACCUMULATORS 6 2 4 APPLICATIONS OF HYDRAULIC ACCUMULATORS ENERGY STORAGE EMERGENCY SOURCES OF ENERGY COMPENSATION FOR LARGE FLOW DEMANDS PUMP UNLOADING REDUCING THE ACTUATOR’S RESPONSE TIME MAINTAINING CONSTANT PRESSURE THERMAL COMPENSATION SMOOTHING OF PRESSURE PULSATIONS LOAD SUSPENSION ON LOAD TRANSPORTING VEHICLES ABSORPTION OF HYDRAULIC SHOCKS HYDRAULIC SPRINGS 6 3 HYDRAULIC FILTERS 6 4 HYDRAULIC PRESSURE SWITCHES 6 4 1 PISTON-TYPE PRESSURE SWITCHES 6 4 2 BOURDON TUBE PRESSURE SWITCHES 6 4 3 PRESSURE GAUGE ISOLATORS 6 5 EXERCISES 6 6 NOMENCLATURE APPENDIX 6A SMOOTHING PRESSURE PULSATIONS BY ACCUMULATORS APPENDIX 6B ABSORPTION OF HYDRAULIC SHOCKS BY ACCUMULATORS NOMENCLATURE AND ABBREVIATIONS HYDRAULIC ACTUATORS 7 1 INTRODUCTION 7 2 HYDRAULIC CYLINDERS 7 2 1 THE CONSTRUCTION OF HYDRAULIC CYLINDERS 7 2 2 CYLINDER CUSHIONING 7 2 3 STOP TUBE 7 2 4 CYLINDER BUCKLING 7 2 5 HYDRAULIC CYLINDER STROKE CALCULATIONS 7 2 6 CLASSI? CATIONS OF HYDRAULIC CYLINDERS 7 2 7 CYLINDER MOUNTING 7 2 8 CYLINDER CALIBERS 7 3 HYDRAULIC ROTARY ACTUATORS 7 3 1 ROTARY ACTUATOR WITH RACK AND PINION DRIVE 7 3 2 PARALLEL PISTON ROTARY ACTUATOR 7 3 3 VANE-TYPE ROTARY ACTUATORS 7 4 HYDRAULIC MOTORS 7 4 1 INTRODUCTION 7 4 2 BENT-AXIS AXIAL PISTON MOTORS 7 4 3 SWASH PLATE AXIAL PISTON MOTORS 7 4 4 VANE MOTORS 7 4 5 GEAR MOTORS 7 5 EXERCISES 7 6 NOMENCLATURE APPENDIX 7A CASE STUDIES: HYDRAULIC CIRCUITS HYDRAULIC SERVO ACTUATORS 8 1 CONSTRUCTION AND OPERATION APPLICATIONS OF HYDRAULIC SERVO ACTUATORS 8 2 1 THE STEERING SYSTEMS OF MOBILE EQUIPMENT 8 2 2 APPLICATIONS IN MACHINE TOOLS 8 2 3 APPLICATIONS IN DISPLACEMENT PUMP CONTROLS 8 3 THE MATHEMATICAL MODEL OF HSA 8 4 THE TRANSFER FUNCTION OF HSA 8 4 1 DEDUCTION OF THE HSA TRANSFER FUNCTION, BASED ON THE STEP RESPONSE 8 4 2 DEDUCING THE HSA TRANSFER FUNCTION ANALYTICALLY 8 5 VALVE-CONTROLLED ACTUATORS 8 5 1 FLOW CHARACTERISTICS 8 5 2 POWER CHARACTERISTICS 8 6 EXERCISES 8 7 NOMENCLATURE APPENDIX 8A MODELING AND SIMULATION OF A HYDRAULIC SERVO ACTUATOR A MATHEMATICAL MODEL OF THE HSA SIMULATION OF THE HSA ELECTROHYDRAULIC SERVOVALVE TECHNOLOGY 9 1 INTRODUCTION 9 2 APPLICATIONS OF ELECTROHYDRAULIC SERVOS 9 3 ELECTROMAGNETIC MOTORS 9 4 SERVOVALVES INCORPORATING FLAPPER VALVE AMPLI? ERS 9 4 1 SINGLE-STAGE SERVOVALVES 9 4 2 TWO-STAGE ELECTROHYDRAULIC SERVOVALVES 9 5 SERVOVALVES INCORPORATING JET PIPE AMPLI? ERS 9 6 SERVOVALVES INCORPORATING JET DE? ECTOR AMPLI? ERS 9 7 JET PIPE AMPLI? ERS VERSUS NOZZLE FLAPPER AMPLI? ERS 9 8 EXERCISES MODELING AND SIMULATION OF ELECTROHYDRAULIC SERVOSYSTEMS 10 1 INTRODUCTION 10 2 ELECTROMAGNETIC TORQUE MOTORS 10 2 1 INTRODUCING MAGNETIC CIRCUITS 10 2 2 MAGNETIC CIRCUIT OF AN ELECTROMAGNETIC TORQUE MOTOR 10 2 3 ANALYSIS OF TORQUE MOTORS 10 3 FLAPPER VALVES 10 4 MODELING OF AN ELECTROHYDRAULIC SERVO ACTUATOR 10 5 EXERCISES 10 6 NOMENCLATURE APPENDIX 10A MODELING AND SIMULATION OF AN EHSA NUMERICAL VALUES OF THE STUDIED SYSTEM TORQUE MOTORS SINGLE-STAGE ELECTROHYDRAULIC SERVOVALVES TWO-STAGE ELECTROHYDRAULIC SERVOVALVES ELECTROHYDRAULIC SERVO ACTUATORS (EHSAS) APPENDIX 10B DESIGN OF P, PI, AND PID CONTROLLERS INTRODUCTION TO PNEUMATIC SYSTEMS 11 1 INTRODUCTION 11 2 PECULIARITIES OF PNEUMATIC SYSTEMS 11 2 1 EFFECTS OF AIR COMPRESSIBILITY 11 2 2 THE EFFECT OF AIR DENSITY 11 2 3 THE EFFECT OF AIR VISCOSITY 11 2 4 OTHER PECULIARITIES OF PNEUMATIC SYSTEMS 11 3 ADVANTAGES AND DISADVANTAGES OF PNEUMATIC SYSTEMS 11 3 1 BASIC ADVANTAGES OF PNEUMATIC SYSTEMS 11 3 2 BASIC DISADVANTAGES OF PNEUMATIC SYSTEMS 11 4 BASIC ELEMENTS OF PNEUMATIC SYSTEMS 11 4 1 BASIC PNEUMATIC CIRCUITS 11 4 2 AIR COMPRESSORS 11 4 3 PNEUMATIC RESERVOIRS 11 4 4 AIR FILTERS 11 4 5 AIR LUBRICATORS 11 4 6 PNEUMATIC CONTROL VALVES 11 5 CASE STUDIES: BASIC PNEUMATIC CIRCUITS 11 5 1 MANUAL CONTROL OF A SINGLE- ACTING CYLINDER 11 5 2 UNIDIRECTIONAL SPEED CONTROL OF A SINGLE-ACTING CYLINDER 11 5 3 BIDIRECTIONAL SPEED CONTROL OF A SINGLE-ACTING CYLINDER 11 5 4 OR CONTROL OF A SINGLE-ACTING CYLINDER 11 5 5 AND CONTROL OF A SINGLE-ACTING CYLINDER 11 5 6 AND CONTROL OF SINGLE-ACTING CYLINDERS; LOGIC AND CONTROL 11 5 7 LOGIC NOT CONTROL 11 5 8 LOGIC MEMORY CONTROL 11 5 9 BIDIRECTIONAL SPEED CONTROL OF A DOUBLE-ACTING CYLINDER 11 5 10 UNIDIRECTIONAL AND QUICK RETURN CONTROL OF A DOUBLE-ACTING CYLINDER 11 5 11 DUAL PRESSURE CONTROL OF A DOUBLE- ACTING CYLINDER 11 5 12 SEMI-AUTOMATIC CONTROL 11 5 13 FULLY AUTOMATIC CONTROL OF A DOUBLE-ACTING CYLINDER 11 5 14 TIMED CONTROL OF A DOUBLE- ACTING CYLINDER 11 5 15 BASIC POSITIONAL CONTROL OF A DOUBLE-ACTING CYLINDER 11 5 16 ELECTRO-PNEUMATIC LOGIC AND 11 5 17 ELECTRO-PNEUMATIC LOGIC OR 11 5 18 ELECTRO-PNEUMATIC LOGIC MEMORY 11 5 19 ELECTRO-PNEUMATIC LOGIC NOT 11 6 EXERCISES 11 7 NOMENCLATURE REFERENCES