28-12-2012, 06:49 PM
Hydraulic Pumps
1Hydraulic.ppt (Size: 725.5 KB / Downloads: 93)
Types
Non-Positive Displacement
Fans
Fluid couplers
Positive Displacement
Gear
Vane*
Piston*
Can be variable displacement, including pressure compensated and load sensing.
Inefficiency
Leakage: you get less flow from a pump than simple theory suggests.
Increases with larger pressure difference
Friction: it takes some torque to turn a pump even if there is no pressure rise
Is more of a factor at low pressures