| 摘要 |
PROBLEM TO BE SOLVED: To perform a pump effect of a rib and to prevent problems such as lip breakage, under pressure of oil. SOLUTION: This oil seal forms a stepped rib 8 having high and low two steps on an outer tilt surface of a seal lip 1, at pressure sealing. In pressure sealing, by forming the rib 8 on the outer tilt surface of the seal lip 1, pump action pushing back lubricant to the inside of seal lip 1 at shaft rotating can be remarkably performed. The rib 8 is raised in a longitudinal direction at high and low two steps, and the length of a lower part of the rib 8 is set to be long or short according to the level of lubricant pressure, which can prevent the breakage of the lip at the time of shaft rotating caused by high pressure of the lubricant. |
