Hydraulic pumps were designed to work under the principle of mechanical energy sources in order to be able to pressurize fluids. The high-pressure created by the hydraulic pumps causes the fluids to flow to the outlets of the pump.

There a few different choices available for hydraulic pump types. These types include the axial piston, the radial piston, the internal gear, the external gear, and the vane. The axial piston hydraulic pump uses an piston that is axially-mounted to pressurize fluids and the radial piston hydraulic pump uses a piston that is radially-mounted about a central axis to pressurize fluids. The fluid is pressurized by the mechanical motion of the pump’s power source that moves the piston through a chamber. An internal gear hydraulic pump uses internal gears to pressurize fluids while an external gear hydraulic pump uses external gears to pressurize fluids. When the power source of the pump causes the internal gears or external gears to turn, the fluids become pressurized and start to be forced through the pump outlets. A vane hydraulic pump uses a vane to pressurize fluid. The vane rotates causing the blades on the vane to force the fluids out of the pumps’ outlet.

Hydraulic pump stages include single stage, double stage, triple stage, and four or more pump stages. Hydraulic pumps also include continuous operating pressure, maximum operating pressure, operating speed, operating horsepower, operating temperature, maximum fluid flow, maximum fluid viscosity, displacement per revolution and pump weight.