| 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 dust cover is provided together with a lip seal member and a slinger. The 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. The dust cover exerts a dust shake-off action due to a centrifugal force during shaft rotation, and a labyrinth seal action due to the formation of a minute gap between the dust cover and the lip seal member. The lip seal member is provided with a main lip and dust lip. The dust lip is provided with: a first bellows part that comprises a rubber-like elastic body, is subjected to atmospheric pressure at the inner peripheral surface and is subjected to internal pressure between the lips at the outer peripheral surface; a second bellows part that is subjected to atmospheric pressure at the outer peripheral surface and is subjected to internal pressure between the lips at the inner peripheral surface; and a lip end. The pressure-receiving area of the first bellows part is established so as to be larger than that of the second bellows part. |
