Automotive water pump bearing

A water pump bearing, comprising; a pump shaft having an outer circumferential surface; an outer ring around the shaft the outer ring having an inner circumferential portion; the outer ring having an axial end face at a lateral side of the bearing; a rolling member located between the outer ring and the pump shaft enabling relative rotation between the outer ring and the pump shaft; a seal at the shaft and the outer ring located at the axial end of the outer ring and shaped and positioned for sealing an internal area of the bearing between the outer ring and the shaft, the seal comprising; a ring shaped first seal comprising a first elastic member, and having a first outer circumferential portion fixed to the inner circumferential portion of the outer ring and having a first inner circumferential portion which is in sliding-contact with the outer circumferential surface of the pump shaft; a fitting groove formed in the inner circumferential surface of the outer ring, the first outer circumferential portion of the first seal bearing fitted in the fitting groove in the inner circumferential surface of the outer ring;

A first portion of the first elastic member extending toward the pump shaft for making sliding-contact with the outer circumferential surface of the pump shaft, the first portion of the first elastic member comprising a first lip extending diagonally and axially inward to make sliding-contact with the outer circumferential surface of the pump shaft and also comprising a second lip extending diagonally and axially outward to also make sliding-contact with the outer circumferential surface of the pump shaft, whereby the first and the second lips are spaced apart along and contact the pump shaft; Automotive water pump bearing, a ring-shaped second seal disposed axially outward of the first seal and nearer to the axial end of the outer ring than the first seal, the second seal having a second inner circumferential portion fixed to the outer circumferential portion of the pump shaft and having a second outer circumferential portion in sliding-contact with the outer ring; the second seal comprising a cylindrical portion extending in an axial direction and fixed to the pump shaft and further comprising a flange extending radially from the cylindrical portion and toward the outer ring; a portion of the second seal flange extending toward the outer ring and the flange portion comprises a third lip in sliding-contact with the axially outer end face of the outer ring.

Further, in this embodiment the elastic member 24 of the second seal unit 20 extends to an inner circumferential edge portion of the cylindrical portion 21 of the ring reinforcement 23 , forming a projection 34 . When the inner circumferential portion of the second seal unit 20 is fixed to the outer circumferential portion of the pump shaft 53 , this fixes the projection 34 of an elastic material with the metal outer circumferential surface 53 a of the pump shaft 53 , in addition to fitting of metal materials between the metal cylindrical portion 21 and the metal outer circumferential surface 53 a of the pump shaft 53 . Therefore, sealing capacity can be improved.