Radial piston pump

If the workspace is filled from "outside" it's called an outside impinged radial piston pump (but inside braced) (picture 2).

[citation needed] The general mode of operation will be explained at the movement of one pumping piston by means of picture 1: The outer ring for bracing of the pumping pistons is in eccentric position to the hollow shaft in the center.

After a rotation angle of 180° it is finished and the workspace of the piston is filled with the moved medium.

From this point on the piston displaces the previously sucked medium in the pressure channel of the pump.

These kinds of piston pumps are characterized by the following advantages: A disadvantage is the bigger radial dimensions in comparison to the axial piston pump, but it could be compensated with the shorter construction in axial direction.