Radial oil seal

A radial oil seal adapted to be disposed between the inner peripheral surface of a bore in a housing and the outer peripheral surface of a rotation shaft inserted into the housing bore for sealing fluid in the housing, the radial oil seal comprising:

• a first seal ring having a seal lip formed of rubber, the seal lip being in contact at its distal end with the outer peripheral surface of the rotation shaft so as to provide a first sealing part;
• a second seal ring having a seal lip formed of synthetic resin and disposed at the air side of and adjacent the first seal ring, the synthetic resin seal lip extending along the back face of the rubber seal lip and being in contact at its distal end with the outer peripheral surface of the rotation shaft so as to provide a second sealing part;
• a reinforcing ring having a substantial rigidity and disposed at the air side of and adjacent the second seal ring, the reinforcing ring being curved along a bent portion of the synthetic resin seal lip so as to support the back face of the bent portion;
• and an outer ring adapted to be fitted into the inner peripheral surface of the housing bore for firmly holding the radially outer peripheral portions of the first and second seal rings and the reinforcing ring.