| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve a traveling performance of a vehicle based on acceleration performance and fuel consumption performance by reducing rotation torque of a hub rotating with a wheel while securing steering stability. <P>SOLUTION: Both end openings of a space in which balls 14, 14 are blocked by seal rings 16c, 16d having two or three seal lips respectively. The rolling resistance changing on the basis of preload is controlled to be within the range of 0.12-0.23 (N m), the sum of the rotation resistances of both seal rings 16c, 16d on the basis of the friction between each seal lip and the mating surface is controlled to be within the range of 0.06-0.4 (N m). <P>COPYRIGHT: (C)2006,JPO&NCIPI |
