Hydraulic Power System Analysis

Hydraulic Power System Analysis
اسم المؤلف
Arthur Akers, Max Gassman, Richard Smith
التاريخ
7 ديسمبر 2021
المشاهدات
339
التقييم
(لا توجد تقييمات)
Loading...

Hydraulic Power System Analysis
Arthur Akers
Iowa State University
Ames, Iowa, U.S.A.
Max Gassman
Iowa State University
Ames, Iowa, U.S.A.
Richard Smith
Iowa State University
Ames, Iowa, U.S.A.
Contents
1 INTRODUCTION 1
1.1 WHAT IS FLUID POWER? . 1
1.2 A BRIEF HISTORY OF FLUID POWER 2
1.3 FLUID POWER APPLICATIONS, PRESENT
AND FUTURE . 3
1.4 ADVANTAGES OF USING FLUID POWER
SYSTEMS 4
1.5 A PROBABLE FUTURE DEVELOPMENT 5
2 PROPERTIES OF FLUIDS AND THEIR UNITS 7
2.1 BASIC PROPERTIES OF FLUIDS . 7
2.1.1 Example: Conversion Between Viscosity Units . 11
2.2 COMPRESSIBILITY OF LIQUIDS . 12
2.2.1 Example: Bulk Modulus of Multiple Containers . 17
2.2.2 Example: The Oil Spring . 22
3 STEADY STATE MODELING 31
3.1 RATIONALE FOR MODEL DEVELOPMENT . 31
3.2 SOURCE OF EQUATIONS 32
3.3 CONSERVATION OF FLOW AND ENERGY . 34
3.4 FRICTION LOSSES IN PIPES AND
FITTINGS . 36
3.5 BASIC COMPONENT EQUATIONS 38
3.6 WORKED EXAMPLES 40
3.6.1 Example: Oil Temperature Rise in a Hydrostatic
Transmission System 41
3.6.2 Example: A Pump Driving a Motor . 44
3.6.3 Example: Using International System Units (SI) 49
3.6.4 Example: Incorporating Pump and Motor Efficiency
Values 52CONTENTS
3.6.5 Example: Performance of a Flow Regulator Valve . 56
3.6.6 Example: Using an Accumulator . 60
3.7 DISCUSSION 67
4 DYNAMIC MODELING 77
4.1 DEVELOPMENT OF ANALYTICAL
METHODS . 77
4.2 SOFTWARE OPTIONS 78
4.2.1 Equation Solutions . 78
4.2.2 Graphical Solutions 79
4.2.3 Fluid Power Graphical Symbol Solutions . 79
4.3 DYNAMIC EFFECTS . 79
4.3.1 Fluid Compliance 80
4.3.2 Newton’s Second Law Effects . 81
4.4 WORKED EXAMPLES 82
4.4.1 Example: Actuator Controlled by a Servovalve . 82
4.4.2 Example: Hydromechanical Servo 89
4.5 MODELING HINTS AND TIPS . 95
4.6 DISCUSSION 98
5 LINEAR SYSTEMS ANALYSIS 101
5.1 INTRODUCTION . 101
5.2 LINEAR SYSTEMS 102
5.3 THE LAPLACE TRANSFORM . 102
5.4 INVERSION, THE HEAVISIDE EXPANSION METHOD . 109
5.4.1 Repeated Roots in Practice 113
5.4.2 Worked Example of Inversion . 114
5.5 STABILITY . 115
5.6 BLOCK DIAGRAMS . 116
5.6.1 Consolidation of Block Diagrams . 118
5.6.2 Block Diagram for a Spring-Mass-Damper System . 119
5.7 SPRING-MASS-DAMPER TIME RESPONSE TO UNIT STEP
FORCE . 121
5.8 TIME CONSTANT 125
6 FREQUENCY RESPONSE AND FEEDBACK 133
6.1 INTRODUCTION . 133
6.1.1 Heuristic Description 134
6.2 MATHEMATICS OF FREQUENCY RESPONSE . 134
6.3 FREQUENCY RESPONSE DIAGRAMS 136
6.4 USING FREQUENCY RESPONSE TO FIND CONTROLLER
GAIN 145CONTENTS
6.4.1 Example: Hydromechanical Servo Revisited . 147
6.5 SUMMARY . 158
7 VALVES AND THEIR USES 163
7.1 INTRODUCTION . 163
7.2 DIRECTIONAL CONTROL VALVES 164
7.2.1 Flow Force on a Spool . 167
7.2.2 Analysis of Spool Valves 170
7.2.3 Linearized Valve Coefficients . 172
7.2.4 Example: Using the Valve Coefficients 174
7.2.5 Comments on the Worked Example . 178
7.3 SPECIAL DIRECTIONAL CONTROL
VALVES, REGENERATION . 180
7.4 FLAPPER NOZZLE VALVE . 182
7.5 FLOW CONTROL ELEMENTS . 185
7.6 RELIEF VALVES . 187
7.6.1 Direct Acting Type . 187
7.6.2 Pilot Operated Type 189
7.7 UNLOADING VALVE . 189
7.8 PRESSURE REDUCING VALVE 191
7.9 PRESSURE SEQUENCING VALVE . 193
7.10 COUNTERBALANCE VALVE 195
7.11 FLOW REGULATOR VALVE 198
8 PUMPS AND MOTORS 209
8.1 CONFIGURATION OF PUMPS AND
MOTORS 209
8.2 PUMP AND MOTOR ANALYSIS 218
8.2.1 Example: Drive for a Hoist 220
8.3 LEAKAGE . 221
8.3.1 Example: Estimating Pump Performance Coefficient
Cs 224
8.4 FORM OF CHARACTERISTIC CURVES . 225
8.4.1 Volumetric Efficiency 225
8.4.2 Torque Efficiency 227
8.4.3 Example: Estimating Motor Performance 231
8.4.4 Overall Efficiency 232
9 AXIAL PISTON PUMPS AND MOTORS 241
9.1 PRESSURE DURING A TRANSITION . 241
9.1.1 Simulation of the Pressure Transition 243
9.1.2 Results of the Simulation . 245CONTENTS
9.2 TORQUE AFFECTED BY PRESSURE
TRANSITION – AXIAL PISTON PUMP 248
9.2.1 Effect on Torque if the Pressure Change at
Transition Is not Immediate 250
9.3 TORQUE AND FLOW VARIATION WITH
ANGLE FOR MULTICYLINDER PUMPS . 251
9.3.1 Noise 254
10 HYDROSTATIC TRANSMISSIONS 257
10.1 INTRODUCTION . 257
10.2 PERFORMANCE ENVELOPE 259
10.3 HYDROSTATIC TRANSMISSION
PHYSICAL FEATURES . 261
10.4 HYDROSTATIC TRANSMISSION
DYNAMIC ANALYSIS 262
10.4.1 Example: The Soil Bin Drive . 266
10.4.2 Final Comments on the Soil Bin Example 269
11 PRESSURE REGULATING VALVE 277
11.1 PURPOSE OF VALVE 277
11.2 OPERATION OF VALVE . 278
11.3 MATHEMATICAL MODEL OF VALVE 280
11.4 EFFECT OF DAMPING . 283
11.4.1 Example: Solution of Model 285
12 VALVE MODEL EXPANSION 291
12.1 BASIC VALVE MODEL 291
12.2 MODEL EXPANSION . 293
12.2.1 Example: Solution of Model 296
12.3 AN ASSESSMENT OF MODELING . 298
13 FLOW DIVISION 299
13.1 INTRODUCTION . 299
13.2 THE HYDRAULIC OHM METHOD . 299
13.3 BRIEF REVIEW OF DC ELECTRICAL
CIRCUIT ANALYSIS . 300
13.3.1 Methods of Solving DC Networks . 301
13.3.2 Motor and Resistance Equivalence 303
13.4 FLUID POWER CIRCUIT BASIC
RELATIONSHIPS . 304
13.5 CONSOLIDATION OF FLUID POWER
RESISTANCES 307CONTENTS
13.5.1 Example: Invariant Resistances 308
13.5.2 Example: Resistance Dependent on Flow 311
13.6 APPLICATION TO UNSTEADY STATE
FLOW 313
13.6.1 Example: The Resistance Network Method Applied
to Unsteady Flow . 315
13.6.2 Example Results and Discussion . 322
13.7 CONCLUSIONS 329
14 NOISE CONTROL 335
14.1 INTRODUCTION . 335
14.2 DISCUSSION OF METHOD . 336
14.3 MATHEMATICAL MODEL . 337
14.3.1 Derivation of Fluid Analogies to Resistance,
Inductance, and Capacitance . 338
14.3.2 Example: Impedance 344
14.3.3 Development of a Lumped Parameter Model 347
14.3.4 Example: Curing Noise from Tractor Hydraulics 350
14.4 EFFECT OF ENTRAINED AIR IN FLUID . 352
14.5 FURTHER DISCUSSION OF THE
MATHEMATICAL MODEL . 353
14.6 OTHER METHODS OF NOISE CONTROL 353
14.7 DAMPING METHODS 355

كلمة سر فك الضغط : books-world.net
The Unzip Password : books-world.net

تحميل

يجب عليك التسجيل في الموقع لكي تتمكن من التحميل
تسجيل | تسجيل الدخول

التعليقات

اترك تعليقاً