A rotary pump having an adjustable specific delivery volume, preferably a vane pump, the rotary pump comprising: (a) a housing featuring a housing inlet and a low-pressure space, connected to the housing inlet, on a low-pressure side of the pump and featuring a housing outlet and a high-pressure space, connected to the housing outlet, on a high-pressure side of the pump; (b) a delivery chamber into which a delivery chamber inlet connected to the low-pressure space opens on the low-pressure side and into which a delivery chamber outlet connected to the high-pressure space opens on the high-pressure side; (c) a delivery rotor which can be rotated about an axis of rotation in the delivery chamber; (d) a setting structure which can be moved back and forth in a first setting direction and, counter to the first setting direction, in a second setting direction in order to perform a setting movement which adjusts the specific delivery volume of the rotary pump; and (e) at least a first setting chamber for charging the setting structure with a setting pressure of a setting fluid which acts in the second setting direction, (f) wherein the fluid pressure in the high-pressure space acts on a pressure equalisation surface on the outer circumference of the setting structure, and the pressure equalisation surface has a pressure surface asymmetry, resulting in an external additional force (F a) which acts on the setting structure in the first setting direction, wherein (g) the outer circumference of the setting structure has a first sliding surface, for forming a first sealing gap with the housing, and a second sliding surface for forming a second sealing gap with the housing, and (h) the sliding surfaces (3b, 3c) are offset relative to one another, transversely with respect to the first and second setting directions, characterised in that (i) the pressure equalisation surface extends in the circumferential direction from the first sealing gap up to the second sealing gap, (j) such that the normal vector of the pressure equalisation surface for generating the external additional force (F a) points counter to the first setting direction. (a) a housing featuring a housing inlet and a low-pressure space, connected to the housing inlet, on a low-pressure side of the pump and featuring a housing outlet and a high-pressure space, connected to the housing outlet, on a high-pressure side of the pump; (b) a delivery chamber into which a delivery chamber inlet connected to the low-pressure space opens on the low-pressure side and into which a delivery chamber outlet connected to the high-pressure space opens on the high-pressure side; (c) a delivery rotor which can be rotated about an axis of rotation in the delivery chamber; (d) a setting structure which can be moved back and forth in a first setting direction and, counter to the first setting direction, in a second setting direction in order to perform a setting movement which adjusts the specific delivery volume of the rotary pump; and (e) at least a first setting chamber for charging the setting structure with a setting pressure of a setting fluid which acts in the second setting direction, (f) wherein the fluid pressure in the high-pressure space acts on a pressure equalisation surface on the outer circumference of the setting structure, and the pressure equalisation surface has a pressure surface asymmetry, resulting in an external additional force (F a) which acts on the setting structure in the first setting direction, wherein (g) the outer circumference of the setting structure has a first sliding surface, for forming a first sealing gap with the housing, and a second sliding surface for forming a second sealing gap with the housing, and (h) the sliding surfaces (3b, 3c) are offset relative to one another, transversely with respect to the first and second setting directions, characterised in that (i) the pressure equalisation surface extends in the circumferential direction from the first sealing gap up to the second sealing gap, (j) such that the normal vector of the pressure equalisation surface for generating the external additional force (F a) points counter to the first setting direction.