SEALING DEVICE

PROBLEM TO BE SOLVED: To provide a sealing device (of bidirectional type) to allow a mating member in sliding, for example, a rotary shaft, to rotate both in the regular and reverse directions, capable of achieving a low torque operation on the basis of fluid lubrication by thickening the fluid film in the lip sliding part. SOLUTION: The sealing device is structured so that a regularly threaded portion 10 and a reversely threaded portion 11 to generate a pumping action are provided on the slope of a seal lip on the counter-sealing fluid side. A projection 12 is formed on the intermediate surface of the seal lip, while a contact part continuous on a circumference is provided in a part of the projection on the counter-sealing fluid side. The direction of that portion of the projection edge, which is located behind in the rotational direction when the mating party makes regular rotation, is set at least partially so as to incline forward with respect to the rotational direction at that time over the range from the sealing fluid side to the counter-sealing fluid side. The direction of that portion of the projection edge, which is located behind in the rotational direction when the mating party makes reverse rotation, is set at least partially so as to incline forward with respect to the rotational direction at that time over the range from the sealing fluid side to the counter-sealing fluid side. COPYRIGHT: (C)2010,JPO&INPIT