A rotor is positioned eccentrically in a cylindrical housing so that it is almost touching the cylinder. When the rotor starts turning, centrifugal force moves the blades out of the rotor slots and they slide against the internal surface of the cylinder. A cell is formed between two blades creating a volume that changes constantly during rotation. Air enters from the inlet port into a cell when the cell has achieved its maximum air volume. As the cell moves away from the port, its volume becomes smaller and smaller, the air is compressed and the pressure rises. This continues until the pressure in the cell exits through the outlet port.

Lubricated rotary vane pumps use oil to “lubricate” or create the seal between the tip of the vanes and the pump housing. Typical maintenance of this type of pump is: oil changes, oil filter changes and exhaust filter changes.