Cam-Piston Pumps. A cam is used to cause the stroking of the pistons in a cam-piston pump. Two
variations are used: in one the cam rotates and the cylinder block is stationary, and in the other the cam
is stationary and the cylinder block rotates. Both cam-piston pumps are described below:
Figure 1-6. Typical Angular Piston Pump.
Rotating-cam pump. The rotating-cam pump is the one most commonly used in Army
aviation. As the cam turns in a rotating-cam pump (Figure 1-7), its high and low points pass
alternately and in turn under each