Mr. Keller, Dr. Seidel, Dr. Schubert
Gap seal for sealing off the interior in a housing from the outside, a rotating shaft with a revolving ring leading into the housing and a sealing gap being formed between this and a fixed sealing ring. One of the boundary surfaces of the sealing gap has spiral grooves that leave free a spiral-free margin at the inner and outer edges. Formed in the region of the spiral grooves is an annular groove which can be supplied with sealing gas and feeds it to the spiral grooves. In the annular boundary surface of the sealing gap, the spiral grooves run symmetrically – as seen in the direction of running – with respect to their curvature away from the annular groove towards the spiral-free edge acting as a barrier, the symmetry applying both in the region of the annular surface outside the groove and in the annular region enclosed by the groove.