Chapter 7
Source of Hydraulic Power
Power Units and Pumps 167
Power Unit 168
Prime Mover 168
Coupler 169
Pump 169
Reservoir 170
Pressure Control Valve 170
Filters and Strainers 170
Basic Pump 170
Structure of a Basic Pump 171
Operation of a Basic Pump 171
Basic Pump Classifi cations 172
Displacement 172
Fundamental Pumping Motion 172
Fluid Delivery Characteristics 173
Pump Design, Operation, and
Application 174
Gear Pumps 175
Vane Pumps 179
Piston Pumps 180
Screw Pumps 186
Lobe Pumps 187
Centrifugal Pumps 188
Other Pump Designs 189
Additional Design Features of Pumps 190
Variable-Flow Delivery 190
Pressure Compensation 192
Pressure Balancing 194
Dual-Pump Designs 197
Pump and Power Unit Design and Operating
Considerations 198
Interpreting Information Sheets of Pump
Manufacturers 199
Prime Mover Power Requirements 199
Effects of Inlet-Line Design on Pump
Operation 204
Chapter 8
Fluid Storage and Distribution
Reservoirs, Conductors, and
Connectors 209
Reservoir 210
Functions of the Reservoir 210
Construction of a Reservoir 211
Reservoir Confi gurations 213
Sizing the Reservoir 214
Conductors 214
Inherent Design Requirements 214
Types of Conductors 216
Conductor Fittings for System
Assembly 220
Selecting Appropriate Conductors 226
Analysis of Circuit and System
Operation 226
Pressure Rating 226
Flow Characteristics 226
Temperature 227
Interpreting Data Sheets from
Manufacturers 227
Conductor Installation 228
Pipe 228
Tubing 228
Hose 229
Chapter 9
Actuators
Workhorses of the System 233
Hydraulic Cylinders 234
Basic Cylinder 234
Classification of Cylinders 236
Cylinder Cushioning 242
Cylinder Mounting 243
Cylinder Calculations 244
Interpreting Cylinder Manufacturer
Specifi cations 246
Limited-Rotation Hydraulic
Actuators 249
Design and Construction 249
Applications of Limited-Rotation
Actuators 252
Hydraulic Motors 253
Conceptual Hydraulic Motor 253
Basic Motor Design and Operation 254
Basic Motor Circuits 263
Hydrostatic Drives 266
Conceptual Circuit Construction and
Operation 267
Pump-Motor Arrangements 268
Hydrostatic Transmissions 268
Contents 9