| 摘要 |
A sealing unit comprises two rigid, face-to-face shields, one of which is provided with an annular elastomeric member exerting sliding radial sealing pressure on a track of the other shield. The other shield is provided with a radially-outer edge bent in such a manner as to define, on a front outer surface of the shield, a concavity, and, on an inner surface, a corresponding convexity cooperating with an axial annular rib on the elastomeric member, for defining a further seal. |
