| 摘要 |
Provided is a dust seal which exhibits excellent sealing properties and has a function configured so that, even if negative pressure occurs on the bearing side within a device, the function can eliminate the negative pressure, thereby preventing the degradation of a lip contact state so that sliding torque does not increase. A dust seal is mounted on the outside of a bearing section of a device and prevents the entry of dust outside the device into the bearing side within the device, and the dust seal has a seal lip having a side lip structure. Ribs are provided at equally-spaced intervals on the surface of the seal lip, which faces the inside of the device. When the bearing section operates normally, the tip of the seal lip is in close contact along the entire circumference thereof with a counter-member. When negative pressure occurs, the seal lip is deformed, causing a circumferential part of the tip of the lip to open about a rib which serves as the fulcrum, and when the negative pressure is eliminated, the seal lip moves back and the tip of the lip closes. The ribs have a circular arc cross-sectional shape at the contact sections thereof. |
