Abstract: A vacuum vane pump wherein one or more stages are installed in an annular extension of the casing for the pump motor. Each stage has a rotor which is driven by the motor shaft by way of an elastic key, and an annular housing which surrounds and is eccentric relative to the rotor. The housing is pivotable about a pintle which is installed in the end walls of the casing and is parallel to the motor shaft. The width of an annular clearance between the external surface of the housing and the internal surface of the extension can be varied by a radially disposed screw which is mounted in the extension diametrically opposite a spring-loaded abutment for the housing. The components of each stage are biased to predetermined axial positions by springs which react against the extension and bias one end wall of the casing against the adjacent housing and rotor, either directly or by way of a partition.