A rotary vane vacuum pump can be an oil-sealed rotary displacement pump. The pumping program consists of a housing (1), an eccentrically set up rotor (2), vanes that move radially under spring push (3) and the inlet and outlet (4). … The Rotor moves by making use 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 conditioning and automatic-transmitting pumps. Pumps for mid-range pressures consist of applications such as carbonators for fountain soft-drink dispensers and espresso espresso machines.
The simplest vane pump has a circular rotor rotating inside a larger circular cavity. The centers of these two circles are offset, leading to 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).