center manner and mounted in a radial direction the inner rotor 3 arranged on the shaft 2 in a torque proof manner is located within the outer rotor 13 rotor 3 together with the shaft 2 are eccentric with respect to the recess in the rotor accommodating plate 10 and the outer rotor 13 the inner rotor 3 is provided with external teeth and the outer rotor 13 is provided with internal teeth these teeth are in meshing engagement with each other due to the said eccentricity a delivery cavity is formed between inner rotor and outer rotor which is not apparent from the figures the face 9 of the bearing member 6 facing the inner rotor 3 is configured as an axial bearing for the inner rotor 3 and the outer rotor 13 for this purpose the face 9 has a low surface roughness for example in a range of ra 0 1 and a narrow tolerance levelness on the side opposite to the set of rotors on the top in the figures a pin 36 is received in a ptfe sleeve 37 within a pot shaped cover 15 as the housing cover pin 36 and ptfe sleeve 37 form an axial floating bearing for the shaft 2 and serve as spacers for an internal magnet 32 described below the height of the sleeve 12 in the axial direction of the shaft 2 is matched to the thicknesses of kidney plate 11 rotor accommodating plate 10 and expanded region 7 and is slightly smaller than the sum of the thicknesses of said components so that they are centered by the sleeve 12 and trapped.