How Vane Pumps Work
Despite the different configurations, most vane pumps operate under the same general principle described below.
1. A slotted rotor is eccentrically supported in a cycloidal cam. The rotor is located close to the wall of the cam so a crescent-shaped cavity is formed. The rotor is sealed into the cam by two sideplates. Vanes or blades fit within the slots of the impeller.
As the rotor rotates (yellow arrow) and fluid enters the pump, centrifugal force, hydraulic pressure, and/or pushrods push the
vanes to the walls of the housing. The tight seal among the vanes, rotor, cam, and sideplate is the key to the good suction
characteristics common to the vane pumping principle.
2. The housing and cam force fluid into the pumping chamber through holes in the cam (small red arrow on the bottom of the pump).
Fluid enters the pockets created by the vanes, rotor, cam, and sideplate.
3. As the rotor continues around, the vanes sweep the fluid to the opposite side of the crescent where it is squeezed through
discharge holes of the cam as the vane approaches the point of the crescent (small red arrow on the side of the pump).
Fluid then exits the discharge port.