A liquid-ring vacuum pump comprises a pump casing and a shaft eccentrically mounted in the pump casing. An impeller and a rotor of a drive motor are connected to the shaft. A disk cam is arranged parallel to the impeller. A first main bearing for the shaft is arranged between the impeller and the rotor of the drive motor, on the plane of the disk cam. The impeller is arranged between the first main bearing and a second main bearing. The arrangement of the bearings prevents the shaft from bending, thus allowing the leakage gap between the impeller and the disk cam to be kept small.