A Vane Pump is a type of positive displacement pump. It uses the back and forth motion of the rectangular shaped vanes inside slots to move fluids. They are sometimes also referred to as sliding vane pumps.
A slotted rotor is eccentrically supported inside a cycloidal cam. The rotor is located close to the wall of the cam such that a crescent-shaped cavity is formed. The rotor is sealed into the cam by two side plates. Vanes or blades fit within the slots of the impeller.
As the rotor rotates and fluid enters the pump, centrifugal force, hydraulic pressure, and/or pushrods pushes the vanes to the walls of the housing. A tight seal in the vanes, rotor, cam, and side plate is important for good suction characteristics described in the vane pumping principles.
The housing and cam forces the fluid into the pumping chamber through the holes located in the cam. Fluid enters the pockets created by the vanes, rotor, cam, and side plate.
As the rotor rotates, the vanes sweep the fluid to the opposite side of the crescent. This fluid is then squeezed through discharge holes of the cam as the vane approaches the point of the crescent. This is followed by the exiting of the fluid from the discharge port i.e. the outlet.