PROBLEM TO BE SOLVED: To provide a wheel supporting rolling bearing unit which is constructed to prevent a cover from falling off one end in the axial direction of an outer ring when temperature rise in an internal space existing on the inner-diameter side of the outer ring involves pressure rise in the internal space.SOLUTION: In a cylindrical part 17a of a cover 16a at its axial intermediate portion located below a vehicle with respect to the circumferential direction in the state that a wheel supporting rolling bearing unit 1b is assembled on the vehicle, a vent hole 23 is provided while passing through the cylindrical part 17a in the radial direction. A seal lip 26 of a seal material 25 provided at the front end of the cylindrical part 17a is put in slide contact with the outer peripheral face of a shoulder part 28 of an inner ring 11 throughout its periphery. An axial distance L from the axial inner edge of the outer peripheral face of the shoulder part 28 to a slide contact area between the front edge of the seal lip 26 and the outer peripheral face of the shoulder part 28 is set longer than an axial distance d from the axial inner edge of the inner peripheral face of a knuckle pilot part 20 to an opening of the vent hole 23 (L>d).SELECTED DRAWING: Figure 2
【課題】外輪の内径側に存在する内部空間の温度上昇に伴いこの内部空間内の圧力が上昇した場合でも、前記外輪の軸方向片端部からカバーが脱落する事を防止できる構造を実現する。【解決手段】カバー16aの円筒部17aのうち、円周方向に関して、前記車輪支持用転がり軸受ユニット1bを車両に組み付けた状態でこの車両の下方に位置する部分の軸方向中間部に、前記円筒部17aを径方向に貫通する状態で通気孔23を設ける。又、この円筒部17aの先端部に設けたシール材25のシールリップ26を、内輪11の肩部28の外周面に全周に亙り摺接させる。この肩部28の外周面の軸方向内端縁から、前記シールリップ26の先端縁とこの肩部28の外周面との摺接部までの軸方向距離Lを、ナックルパイロット部20の内周面の軸方向内端縁から前記通気孔23の開口部までの軸方向距離dよりも大きくする(L>d)。【選択図】図2
WHEEL SUPPORTING ROLLING BEARING UNIT
車輪支持用転がり軸受ユニット
2016-03-31
Patent
Electronic Resource
Japanese