Patent ID: 8366117

Claim:
A sealing device comprising: an exterior sealing member that is annularly molded using an elastomer and includes a fitting portion and a sealing lip portion, the fitting portion being configured to be fitted in a housing hole, the sealing lip portion is configured to be pressed against an outer circumference surface of a shaft; a reinforcing ring that is formed into an annular shape and retains the fitting portion of the exterior sealing member in an outer circumference thereof, the reinforcing ring having a leading end portion from which the sealing lip portion of the exterior sealing member extends, the reinforcing ring being configured to be disposed in the housing hole to surround an outer circumference of the shaft and to press the fitting portion of the exterior sealing member against an inner circumference surface of the housing hole; a retainer that is encompassed within the reinforcing ring so that the interior of the reinforcing ring surrounds the exterior of the retainer; an auxiliary sealing member in the reinforcing ring that has one end portion that is pinched and retained between the retainer and the reinforcing ring and the other end portion that is pressed against the outer circumference surface of the shaft; and an elastic engagement unit that is provided between the retainer and the reinforcing ring, the elastic engagement unit being configured to deform elastically to permit the retainer to be accommodated in the reinforcing ring when the retainer is mounted in the reinforcing ring and being configured to be elastically restored to engage with a counterpart to prevent the retainer from dropping out of the reinforcing ring when the auxiliary sealing member is pinched and retained between the retainer and the reinforcing ring.