BEARING DEVICE FOR WHEEL, HAVING ROTATION SPEED DETECTION DEVICE

摘要

There is provided, according to the present invention, there is provided a wheel bearing apparatus incorporated with a wheel speed detecting apparatus comprising: an outer member having double row outer raceway surfaces formed on its inner circumferential; an inner member including a hub wheel having a wheel mount flange formed integrally therewith at one end thereof and a cylindrical portion axially extending from the wheel mount flange, and an inner ring fitted on the cylindrical portion of the hub wheel, double row inner raceway surfaces opposite to the double row outer raceway surfaces being formed on the outer circumferential surfaces of the hub wheel and inner ring respectively; double row rolling elements arranged between the outer and inner raceway surfaces; an encoder mounted on the outer circumferential surface of the inner ring; an annular sensor holder arranged on the end of the outer member oppositely to the encoder; and a wheel rotation speed detecting sensor molded integrally with the sensor holder and arranged oppositely to the encoder via a predetermined radial gap characterized in : that the encoder has an annular ring configuration and its characteristics varying alternately and equidistantly along its circumferential direction; that a seal is arranged at the inboard side of the encoder via the sensor holder, the seal including first annular sealing plate and second annular sealing plate and being mounted on the sensor holder and the inner ring respectively and oppositely toward each other.