Adjustable vane cell pump

An adjustable vane cell pump is described with a rotor (2) arranged in a housing (1) and a displaceable lifting ring (3). The working chamber between lifting ring (3) and rotor (2) is sealed laterally by side parts (6,7). The one side part (6) is axially displaceable and acted upon on both end faces (13, 14) in such a way that a resulting force is produced in the direction of the rotor (2). The second side part (7) is fixed to the housing and is formed by a housing cover. The lifting ring (3) is clamped between two diametrically opposed adjusting elements (10, 11). The outer circumferential surface (15) is so inclined in the bearing area of the two adjusting elements (10, 11) that in addition to the pressure-related clamping forces, which are applied by the adjusting elements (10, 11), a pressure-related axial displacement force acts on the lifting ring (3) and constantly presses this in the direction of the housing cover. The axially displaceable side part (6) can adjust its postion under the effect of the hydraulic forces, so that slight air gaps between lifting ring (3) and/or rotor (2) and both side parts (6,7) and a good volumetric efficiency are produced.