| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a structure, with which both cost reduction and secured durability can be achieved. <P>SOLUTION: The whole outer face of a shell type outer ring 9 is covered with a chemical conversion coating such as an iron phosphate coating having corrosion resistance. The chemical conversion coating is exposed from the outer face of the shell type outer ring 9 at its portion internally fitted to a circular hole 6a of a yoke 2a to abut on the inner peripheral face of the circular hole 6a. A portion deviating from the circular hole 6a, with which the tips of seal lips 17, 18 constituting a seal ring 14 may have slide contact, is covered with a coating 21 to sufficiently improve its corrosion resistance. Without the need for manufacturing the shell type outer ring 9 of an expensive stainless steel plate, there is no event that the surface roughness of the portion is degraded by rust. The tips of the seal lips 17, 18 are preventive of sealing performance deterioration due to wear. <P>COPYRIGHT: (C)2012,JPO&INPIT |
