| 摘要 |
<P>PROBLEM TO BE SOLVED: To increase the sealability of a pulley 2 at stoppage or in low speed rotating while suppressing an increase in resistance when the pulley 2 is rotating at high speeds. <P>SOLUTION: The pulley 2 is supported on a rotating shaft 21 through a roller clutch 3 and a support bearing 4. The tip edge of a seal lip 28 forming a seal ring 26 supported on the base end part of the pulley 2 is brought into contact with a sloped surface 29 formed at the tip part of a housing 22. The tip edge of the seal ring 28 is brought into contact with all the periphery of the sloped surface 29 when the pulley 2 is stopped or running at low speeds. Whereas the tip edge of the seal lip 28 is separated from the sloped surface 29 based on a centrifugal force when the pulley 2 is rotating at high speeds. In this state, the entry of foreign matter to the inner diameter side of the pulley 2 can be prevented by the slinger action of the base end face of the pulley 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
