A rotary vane vacuum pump can be an oil-sealed rotary displacement pump. The pumping system consists of a casing (1), an eccentrically set up rotor (2), vanes that move radially under springtime power (3) and the inlet and wall plug (4). … The Rotor moves with the aid of a motor mounted on it.
Uses. Vane pumps are generally used as high-pressure hydraulic pumps and in automobiles, including supercharging, power-steering, air-con and automatic-transmitting 
pumps. Pumps for mid-range pressures include applications such as for example carbonators for fountain soft-drink dispensers and espresso coffee machines.
The simplest vane pump includes a circular rotor rotating in the larger circular cavity. The centers of these two circles are offset, causing eccentricity. … The action of the vane drives out the same volume of fluid with each rotation. Multistage rotary-vane vacuum pumps can attain pressures as low as 10 mbar (0.0001 Pa).