| 摘要 |
PURPOSE:To improve a seal effect, by a method wherein an annular groove formed in succession in the peripheral direction of a rotary shaft is formed in the seal surface with a rotary shaft of a lip. CONSTITUTION:An annular groove 9 is formed in the seal surface with a rotary shaft 2 of a lip 6. Since the thickness of the annular groove 9 part of the lip 6 is decreased to a value lower than that of the other part, said part is apt to deform by press as a result of a pressure on the seal fluid side being exerted thereon. As a result, the potions, located at both parts of the annular groove 6, of the seal surface are forced into especially firm pressure contact with the outer peripheral surface of the rotary shaft 2. Since the annular groove 9 is formed in succession in a circumferential direction, contact part also extends in succession in a circumferential direction. Besides, since two annular contact parts per one annular groove 9 are provided, a double seal action is produced. Thus, a double seal action causes production of an excellent seal effect both during rotation and during a stop compared with a conventional device. |
