| 摘要 |
PROBLEM TO BE SOLVED: To establish compatibility between sealability, which is exerted when biting of foreign matter is caused by securement of contact width of a lip tip 1b, and sealability, which is exerted in an initial state of sealing brought about by securement of contact pressure, at a high level.SOLUTION: A seal surface 1a of a main seal lip 1 includes a first slope 4 with a seal surface angle γ, a second slope 5 with a seal surface angle α, and a slope with a seal surface angle &bgr;, which are arranged in order on the side 3 of an unsealed fluid from a lip tip 1b. Relationships among the seal surface angles are expressed by the inequality: α<γ≤&bgr;. At least the first and second slopes 4 and 5 are brought into contact with a shaft 7. |
