Wheel bearing and sealing device therefor

A wheel bearing which comprises an inner member, an outer member, a circular row of rolling elements interposed between the inner and outer members, and a sealing device sealing an annular end space delimited between the inner and outer members, said sealing device comprising:

• first and second annular sealing plates secured respectively to one of the inner and outer members and the other thereof, and disposed in face-to-face relation to each other;
• each of the first and second annular sealing plates including a cylindrical wall and a radial wall assembled together to represent a generally L-shaped section;
• the first annular sealing plate being mounted on one of the inner and outer members which is rotatable relative to the other of the inner and outer members, with the radial wall positioned on one side adjacent an exterior of the bearing;
• a first elastic member mixed with a powder of magnetic particles and bonded by vulcanization to the radial wall of the first annular sealing plate, the first elastic member being formed with a magnetized portion in which opposite magnetic poles are formed alternately in a direction circumferentially thereof;
• the second sealing plate including an elastic sealing member, the elastic sealing member being formed integrally with a side sealing lip slidingly engageable with the radial wall of the first annular sealing plate and a radial sealing lip slidingly engageable with the cylindrical wall of the first annular sealing plate;
• the cylindrical wall of the second annular sealing plate being spaced a slight radial gap from a free periphery of the radial wall of the first annular sealing plate;
• and
• a second elastic member, made of a material different from that of the first elastic member bonded to the radial wall and interposed at an engagement of the first annular sealing plate with such one of the inner and outer members which is rotatable.