Abstract

A seal structure is disclosed in which self-aligning bearings have flanges fastened to respective ends of the inner and outer rings. The flanges overlap with an annular gap between them. A sealing ring having two sealing lips is fixed to one of the flanges. The other flange has an axially extending portion which is concentric with the axis of the bearing and has a spherical outer surface. In one embodiment, one sealing lip extends across the gap and presses against the spherically curved surface. This sealing lip remains sealed to the outer surface even when the bearing rings swing out of alignment with one another. The second sealing lip rests against an approximately radial portion of one of the flanges to improve the sealing action. A second embodiment contains an additional third sealing lip, which is obliquely inclined toward the spherically curved portion of the flange. A third embodiment contains a further leg attached to the spherically curved portion of the flange which extends close to the other surface flange, creating a labyrinth pre-seal which is better able to retain the lubricant in the bearing space.