| 摘要 |
<P>PROBLEM TO BE SOLVED: To increase the sealability of a shaft portion driving a valve and prevent the sealability from lowering even if the valve is deformed due to thermal expansion in an exhaustion switching valve drive device driving the valve for switching or opening/closing a passage for exhaust emission among the exhaust emission passages of the internal combustion engine. <P>SOLUTION: Seal rings 34 to 36 are so formed that the movement of a shaft 22 in the axial L1 direction by a bearing 33 and a mesh 37, the seal rings 34 and 36 are brought into surface contact with a shaft 22, and the seal ring 35 is brought into surface contact with a shaft insert hole 30. Also, the portions of the seal rings 34 to 36 are so formed that are brought into surface contact with tapered surfaces 34b, 35a, and 36b for converting forces in directions perpendicular to the axis of the shaft 22 into resilient forces to the bearing 33 and mesh 37 sides. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
