US Patent 8141882 Wheel seal

A wheel seal is mainly provided with an annular internal sleeve oil seal. An annular concave inwards is formed at one side of the internal sleeve oil seal to contain one end of an annular outer annular member. A gap is kept between the internal sleeve oil seal and the outer annular member to contain an anti-friction ring and a second barrier. A labyrinth zone that is up and down is formed in the second barrier. Thus, the anti-friction ring is used to not only block foreign matters from entering the wheel seal through the gap and then being damaged, but also effectively transfer the strength from the inner annular member to the outer annular member at the time of installation for increasing the success rate of installation.