Single role: The vane is inlaid in the groove, can slide freely, when the rotation is generated, the vane is thrown to the pump shell under the action of centrifugal force. The vane pump is a positive displacement pump, and the adjacent two vanes move to the bottom When the rotor rotates clockwise, the adjacent two vanes experience the volume increasing process from the bottom to the top. Therefore, the oil absorption (from the fourth quadrant To the second quadrant); from the top to the bottom is the volume reduction process, so press the oil (from the second to the fourth quadrant). Double action: When the motor drives the rotor to rotate, the vane protrudes outwards under the double action of centrifugal force and pressure oil at the bottom of the vane, and the top of the vane sticks to the inner surface of the stator. The four vanes on the four concentric circular arcs respectively form four sealed working oil chambers with the outer surface of the rotor, the inner surface of the stator and the two valve plates. These oil chamber with the rotation of the rotor, seal the working oil chamber produce small to big or small to small changes, can be through the oil distribution window suction port (connected to the suction port) or drain window (connected to the drain port) Inhale or extrude the oil. In the rotor per revolution, each working oil chamber to complete two oil and oil pressure, so called double-acting vane pump, due to symmetrical symmetry between high and low pressure chamber, the shaft force balance, unloading type. Vane pumps equipped with small power, large flow, gas stations, oil depots, chemicals, refineries, aviation kerosene, the best choice for refueling ships.