| 摘要 |
PURPOSE:To maintain sealing ability for a long period through suppression of the occurrence of the crack and abnormal wear of a slide part even when a pressure in a seal space is increased during rotation of a shaft by a method wherein the seal space is communicated with a pressure introduction chamber between the base part of a seal body and an annular protrusion part through a pressure introduction passage. CONSTITUTION:A seal body 20 comprises a base part 21; and an inside diameter lip part 23 extended to the atmosphere B side and brought into contact with the outer peripheral surface of a shaft 6. An annular protrusion part 24 is formed on the outer peripheral surface of a pressure receiving part 22 between the base part 21 and the inside diameter lip 23. In which case, the inner peripheral surfaces of the base part 21 and the pressure receiving part 22 are brought into non-contact with the shaft 6. The end part on the seal space A side of the slide surface 23a of the inside diameter lip part 23 is positioned closer to the seal space A side than the close contact part of the annular protrusion part 24. A pressure introduction chamber 12S is communicated with the seal space A through a pressure introduction hole 15 between the base part 21 and the annular space part 24. This constitution brings the inside diameter lip part 23 into slide over the shaft 6 at a proper bearing. |
