Wheel support bearing assembly

Abstract

To provide a wheel support bearing assembly coupled with the knuckle of a type made of an aluminum alloy, in which an undesirable occurrence of electrocorrosion resulting from a galvanic cell developed at a surface area where the wheel support bearing assembly contacts the aluminum alloy knuckle is substantially eliminated, a wheel support bearing assembly is provided with an outer member ( 1 ) having an inner peripheral surface formed with raceways ( 4 ), an inner member ( 2 ) having raceways ( 5 ) defined therein in alignment with the raceways ( 4 ) in the outer member ( 1 ), and rows of rolling elements ( 3 ) positioned between the raceways ( 4 and 5 ) in the outer and inner members ( 1 and 2 ), respectively. The outer peripheral surface of the outer member ( 1 ) is formed with a vehicle body fitting flange ( 1 a ) for securement of the wheel support bearing assembly to a knuckle ( 14 ) made of an aluminum alloy and the outer peripheral surface of the inner member ( 2 ) is formed with a wheel mounting flange ( 2 a ) for the support of a vehicle wheel. An electrically insulating layer ( 17 ) is provided at a surface area of contact between the outer member ( 1 ) and the knuckle ( 14 ), that is, on a portion of the outer peripheral surface of the outer member ( 1 ) that is received in a bearing bore ( 14 a ) of the knuckle ( 14 ) and one of axial end faces of the vehicle body fitting flange ( 1 a ).

1 . A wheel support bearing assembly rotatably supporting a wheel relative to a vehicle body structure, the wheel support bearing assembly comprising: 
 an outer member having an outer peripheral surface formed with a vehicle body fitting flange to secure the wheel support bearing assembly to a knuckle made of an aluminum alloy, the outer member also having an inner peripheral surface with raceways defined therein, the outer member being made of steel;    an inner member having a wheel mounting flange positioned at one end thereof and also having raceways defined therein in alignment with the raceways of the outer member;    rows of rolling elements positioned between the raceways of the outer member and the raceways of the inner member, respectively; and    an electrically insulating layer provided at a surface area of contact between the outer member and the knuckle, the electrically insulating layer comprising a plated ply with a chromate treated layer thereon, and a coating layer functioning as an electric insulator.