| 摘要 |
In order to provide an oil seal that is capable of reducing sliding torque to a greater extent than when fabric is used as a dust lip, a slinger is provided with a thread groove that provides a pumping action in a radially outward direction to an end face of a flange outside a machine. A lip seal member is provided with a main lip, a rubber-like elastic dust lip, and a similar rubber-like elastic middle lip. The middle lip: has a lip edge that faces the inside of a machine, and closely fits the slinger over the entire circumference; and is provided with an annular first protrusion and a partial circumferential second protrusion in a section that faces the slinger. The first protrusion is provided with a structure that forms a minute gap between the first protrusion and the slinger, making it difficult for dust to pass toward the lip edge. The second protrusion is provided with a structure having a high portion that is higher than the first protrusion, and properly maintains the minute gap when eccentricity is generated on a rotary shaft. |
