A pump having an integrated, electronically commutated direct-current motor with a permanent-magnetic inner rotor arranged in a wet chamber, which inner rotor together with a centrifugal pump impeller forms a compact pump-rotor unit, claw-pole plates (6, 6') arranged in a dry chamber and made of a soft magnetic material, an annular winding and a claw-pole stator, mounted on the claw-pole plates (6, 6') and comprising a soft magnetic return ring arranged around the winding, and a split pot which separates the dry chamber from the wet chamber, characterised by the combination of the following features: a) the claw-pole stator has four claw-pole plates (6, 66) each of which comprises a plurality of claw poles (7, 77) extending parallel to the pump axis and adjoining a ring (8, 88) arranged at right angles to the pump axis; b) two claw-pole plates (6, 66) of the same polarity and two claw-pole plates (6, 66') of opposite polarity cooperate with the same winding; c) the claw-pole plates of the same polarity and opposite polarity are each composed of two claw-pole plates (6, 66, 6', 66') of differing design which nest, so that the claw-poles (7, 77, 7', 77') of two claw-pole plates of the same polarity are at different radial distances from the pump-rotor unit however are arranged in the same angular sector, wherein the radial difference corresponds to the plate thickness of the claw poles which are closer to the pump-rotor unit; d) the length, in an axially-parallel direction, of the claw poles (7, 7') arranged radially closer to the pump-rotor unit is greater than the radius of an inscribed circle bounded by the same claw poles (7, 7'); e) the bending radii (R1, R2) of the nested claw-pole plates (6, 66 and 6', 66' respectively) are at least approximately equal in size in the transition region between the ring (8, 88 and 8', 88' respectively) and the claw poles (7, 77 and 7', 77' respectively), so that a gap between the claw-pole plates (6, 66 and 6', 66' respectively) arises in the transition region; f) a plastics shaped body adjoins, at a side remote from the winding, at least one ring (8, 8') of a claw-pole plate, which plastics shaped body has receiving means (15, 17) for a printed circuit board and clamp cutting connectors, wherein the plastics shaped body is manufactured by encapsulation and at least partially encloses and fixes the four claw-pole plates (6, 6', 66, 66'), whereby the stator forms a compact annular body which only firmly contacts the split pipe via rib-like and/or stud-like regions. a) the claw-pole stator has four claw-pole plates (6, 66) each of which comprises a plurality of claw poles (7, 77) extending parallel to the pump axis and adjoining a ring (8, 88) arranged at right angles to the pump axis; b) two claw-pole plates (6, 66) of the same polarity and two claw-pole plates (6, 66') of opposite polarity cooperate with the same winding; c) the claw-pole plates of the same polarity and opposite polarity are each composed of two claw-pole plates (6, 66, 6', 66') of differing design which nest, so that the claw-poles (7, 77, 7', 77') of two claw-pole plates of the same polarity are at different radial distances from the pump-rotor unit however are arranged in the same angular sector, wherein the radial difference corresponds to the plate thickness of the claw poles which are closer to the pump-rotor unit; d) the length, in an axially-parallel direction, of the claw poles (7, 7') arranged radially closer to the pump-rotor unit is greater than the radius of an inscribed circle bounded by the same claw poles (7, 7'); e) the bending radii (R1, R2) of the nested claw-pole plates (6, 66 and 6', 66' respectively) are at least approximately equal in size in the transition region between the ring (8, 88 and 8', 88' respectively) and the claw poles (7, 77 and 7', 77' respectively), so that a gap between the claw-pole plates (6, 66 and 6', 66' respectively) arises in the transition region; f) a plastics shaped body adjoins, at a side remote from the winding, at least one ring (8, 8') of a claw-pole plate, which plastics shaped body has receiving means (15, 17) for a printed circuit board and clamp cutting connectors, wherein the plastics shaped body is manufactured by encapsulation and at least partially encloses and fixes the four claw-pole plates (6, 6', 66, 66'), whereby the stator forms a compact annular body which only firmly contacts the split pipe via rib-like and/or stud-like regions.