Hydraulic pumps

A Hydraulic is used in hydraulic drive systems.

Hydraulic pumps can be hydrostatic or hydrodynamic.

Hydrostatic pumps are positive displacement pumps.

Hydrostatic pumps can be fixed displacement pumps, in which the displacement (flow through the pump per rotation of the pump) cannot be adjusted, or variable displacement pumps, Mechanical Seal which have a more complicated construction that allows the displacement to be adjusted.