A rotary vane pump is a positive-displacement pump that consists of vanes mounted to a rotor that rotates inside a cavity. In some cases these vanes can have variable length and/or be tensioned to maintain contact with the walls as thepump rotates.

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. … Fluid enters the pockets created by thevanes, rotor, cam, and sideplate.

There are two types of vane pumps: 1. Unbalanced vane pump: Unbalanced vane pumps are of two varieties: Unbalanced vane pump with fixed deliver