| 摘要 |
PROBLEM TO BE SOLVED: To heighten rigidity of a thread protrusion by making the inclination of a rear face inclining backward with respect to the rotating direction of the thread protrusion, easier than that of a front face in a sealing device provided with the thread protrusion on the atmosphere side sliding face of a seal lip. SOLUTION: A thread protrusion is provided with a forward inclining front face 61 and a backward inclining rear face 62 with respect to a rotating direction in a cross section in a width direction. In the case of dividing an apex angle in a front angle 63 and a rear angle 64 at a vertical line, the front angle 63 is set to 55 deg. and the rear angle to 65 deg., for instance, and the inclination of the rear face 62 is formed to be easier than that of the front face 61. In this case, if the inclination of the rear face 62 can be formed to be easier than that of the front face 61 while satisfying the front angle 63 < the rear angle 64, the front and rear faces 61, 62 can be formed at various angles, and the shape can be made also curved shape such as arcuate shape high at the middle part. |
