explained hereinbelow fig2 shows a view of the bearing member 18 and more particularly its end side which faces toward the sealing plate 26 a first groove train 27 is provided in this end side and extends near the outer contour of the bearing member the groove train 27 extends partially concentrical to the shafts of the gears from the high pressure side hd toward the low pressure side nd however it does not extend up to the latter the groove train 27 ends respectively in two groove ends 27a and 27b which extend to the edge of the bearing member a seal 28 of a rubber elastic material is arranged in the groove train a second groove train 29 is formed also concentrically to the shafts of the gears however radially inwardly of the groove train 27 the groove train 29 also extends from a high pressure side to a low pressure side and its ends 29a and 29b extend further toward the low pressure side than the groove ends of the groove train 27 the groove train 29 also has in its central region a recess 29c which leads substantially to a straight line connecting the centers of the shafts a matching seal 30 is arranged in the groove train 29 and is also composed of a rubber elastic material the high pressure side hd is identified by a recess 31 a high pressure opening 32 extends from outside of the housing into the recess at the height of the gears 14 and 15 the low pressure side nd is identified with a recess 33 a low pressure opening 34 extends axis parallel to the high pressure opening.