Rotary Cam Pumps come in many variations.
This animation is also called a Cochrane Rotary Pump. It is not in use now and
is mainly of historical curiosity.
In this model the intake is the lower tube
on the right and the outlet is at the top. The piston slide arm moves around inside
a slot in the casing.
As an eccentric cam rotates the circular plunger (shown
in gray) around the edge of the casing, fluid is swirled around the edge to the
One variation of this type of pump is the Kinney Rotating Plunger
Pump which ejects the fluid through a hollow in the slide pin and a discharge
port on the discharge side of the pump.