Hydraulic Pumps

Hydraulic pumps are the power source for hydraulic control systems. It shows that hydraulic pumps exist in many different configurations, all of which are accompanied by their own advantages and disadvantages. The chapter considers the efficiency of hydraulic pumps in general along with modeling and measuring techniques. Since gear and axial-piston pumps are the most common pump types used in hydraulic control systems, it discusses these pumps in more detail. It describes the control of variable-displacement swash-plate type pumps. The chapter also discusses both the pump flow characteristics and various control designs. The discharge flow characteristics of an axial-piston pump are similar to those of a gear pump in the fact that both pumps exhibit an oscillatory flow ripple that may be roughly described by the flow ripple amplitude. The chapter describes the flow ripple characteristics of an axial-piston pump.