The oil seal overall vulcanized fiber strengthens the outer ring to replace the metal skeleton, so the oil seal can remain flexible even when the diameter is very large, eliminating the deformation during transportation and installation.The special design of the clamp spring groove prevents the spring from falling off accidentally during installation.Additional dust between the pair of lip and the main lip at the painted oil installation and at the same time of improving lubrication, effectively prevent the dust and moisture intrusion, avoids the production of wear and corrosion.