| abstract |
A rolling bearing unit for supporting a wheel, wherein the inner end opening of openings at both ends of a space having balls (14, 14) installed therein is closed by a cap (17a), the outer end opening is closed by a seal ring (16c) having three seal lips, a rolling resistance varying according to a pre-load is restricted in the range of 0.15 to 0.45 N·m, and the rotating resistance of the seal ring (16c) based on a friction between the seal lips and their mating surface is restricted in the range of 0.03 to 0.2 N·m. |