Centrifugal Pump

A centrifugal pump is a rotodynamic pump that uses a rotating impeller to increase the pressure of a fluid. Centrifugal pumps are commonly used to move liquids through a piping system. The fluid enters the pump impeller along or near to the rotating axis and is accelerated by the impeller, flowing radially outward into a diffuser or volute chamber (casing), from where it exits into the downstream piping system. Centrifugal pumps are used for large discharge through smaller heads.
(Source : http://en.wikipedia.org/wiki/centrifugal_pump and thomasnet.com)
1/2 HP Pool Centrifugal H.D. Water Pump