Cassette seal

A cassette seal for sealing off a space to be sealed, comprising:

• an outer ring positioned around a longitudinal axis and having at least one sealing lip;
• an inner ring positioned around said longitudinal axis and having an annular profile opposite to an annular profile of said outer ring, said inner and outer rings surrounding an annular space having an imaginary concentric axis, said sealing lip abutting said inner ring;
• said outer and inner rings forming a gap connection between said annular space and the space to be sealed off by the cassette seal;
• a flange radially coupled to said inner ring and limiting said gap connection, said gap connection being wider on a side of said gap connection turned away from said flange in a plurality of segmental cut-outs uniformly distributed over the circumference of the outer ring, said plurality of segmental cut-outs functioning as ducts between the annular space and the space to be sealed off;
• and
• a conically inclined run-off surface forming a part of a diameter concentrically surrounding said axis and extending in a funnel shape toward said annular space, said run-off surface forming an angle of 30.degree. to 80.degree. with said axis, said ducts being limited in an axial direction on a side facing said flange by said run-off surface, said run-off surface completely surrounding said flange in the axial direction and partially surrounding said sealing lip, wherein said run-off surface includes an extension running in the radial direction and forming a common radial plane with the flange, said extension having at least one seal that is capable of being adjoined to an axially adjacent sealing surface on a side of said extension facing the space to be sealed off.