New turbomolecular pump with central opening for free axial access

Standard turbomolecular pumps show typically one annular active intake area on the high vacuum flange side (single-flow pumps). The central circular part of the inlet of the compressor turbine is blind for pumping. The new design proposes a central opening of a turbomolecular pump all along the axis. This central bore can be used e.g. for mounting of feed throughs, manipulators, windows or for coupling to further vacuum devices, in particular also for enclosing tube-like vacuum systems. This design allows a multi-use of a pumping port at a vacuum vessel without reducing there the pumping speed. Moreover, the new design is ideal for axial or radial differential pumping arrangements as e.g. needed for all gas jet like set-ups or other pressure reduction stages.