| 摘要 |
PURPOSE: To maintain a proper sealing performance by establishing an external shape for securing proper seal clearance between rear shield internal surface and segment external surface, so as to keep a proper interference for a seal used to hermetically close a cavity resulting from a difference between shield inner diameter and segment outer diameter. CONSTITUTION: A difference between the lateral outer diameter L1 of an elliptical segment 10b and the inner diameterϕD of a rear shield 6 is established, so as to give a proper interference value for a wire brush 11 along the left side A1 and right side B1 of a bending direction. Thereafter, the lateral outermost length of the segment 10b is taken at L1 for a proper seal interference. Also, the longitudinal outermost length H1 thereof is taken as equal to L0 for keeping proper clearance, provided that L0 is the outer diameter of a circular segment 10 for a linear tunnel. Then, the segment 10b with the length L1 as a minor axis and the length H1 orthogonal with a bending direction as a major axis is used, thereby providing a proper seal interference for maintaining a seal performance between the outer diameter of the segment 10b and the inner diameter of the shield 6.
|
