Abstract: An axial shaft sealing unit for sealing a stationary machine part relative to a rotatable machine part. The sealing unit includes a slide ring seal mounted on the stationary machine part in a sealing manner and includes a housing with a bottom located transversely to the axis of the slide ring seal, a primary seal forming a sliding ring, a bellows-like secondary seal, and a compression spring arranged between the primary seal and the housing bottom or base. The bellows-like secondary seal is vulcanized in a position which corresponds substantially to its installed position and is held in this position in its operative state by a detachable holder. A counter ring rests directly against a machine component which is non-rotatably connected to the rotatable machine part.

Abstract: A slide ring seal structure for sealing machine elements rotatable about an axis, especially for sealing pump shafts, with an about rotation-symmetric housing which at one end face has a bottom extending transverse to the axis of the seal structure. The slide ring seal structure also has a primary seal designed as slide ring located in the interior chamber of the housing, and further has a bellows-shaped annular secondary seal as well as a spring arranged between the slide ring and the bottom of the housing. The secondary seal has an outer cone which flares in the direction of the sliding surface of the slide ring and has associated therewith a corresponding inner cone of a clamping member coaxially surrounding the secondary seal. The axial position of the clamping member relative to the slide ring and to the secondary seal being determined solely by the axial force exerted upon the clamping member during the installation of the slide ring seal structure.