US Patent 7988436 Vane machine

A vane machine includes a housing with a inlet port and an outlet port, a rotor mounted in a cavity of the housing. The rotor has a faceplate and a guide cylinder mounted eccentrically on an end surface of the housing opposite to the faceplate. The guide cylinder is rotatable and provided with a diametrical face groove open from a side of the faceplate, and one or more working vanes mounted on the faceplate such that the faceplate is rotatable and movable in the grooves of the guide cylinder as the faceplate rotates. The diameter of the guide cylinder 7 is D>4a−L, where e is the eccentricity of the axis of the guide cylinder and the length of the working vane is L≦4e×sin 90°/N, where N is the number of working vanes.