| 摘要 |
<p>A resin lip type seal (1) installed in an annular clearance between a housing (12) and a reciprocating shaft (13) and capable of preventing the shapes of the tip parts (31, 41, 61) of lips (3, 4, 6) fitted to a mating member (12 or 13) from being changed with elapse of time. The shapes of the tip parts (31, 41, 61) of lips (3, 4, 6) are so determined that they comprise, in a well-balanced state, both a function for securing low leak which is the feature of sharp shape and a function for securing oil film thickness which is the feature of R-shape. Flat surfaces (21) with axial widths (W) having edge parts (22) are formed at the tip parts (31, 41, 61) of the lips (3, 4, 6). Also, the axial widths of the flat surfaces (21) are determined to be 5 to 30% of the overall axial widths (A) of the lips (3, 4, 6).</p> |
