| 摘要 |
PURPOSE:To improve pump performance by forming ribs having the angle smaller than the angle formed by ribs and the direction of the seal lip tip in relation to the seal lip tip edge direction, and lower than the ribs between many ribs, so that one side ends may be concentrated on the tips. CONSTITUTION:Ribs 8 lower than ribs 7 are formed between many ribs 1 formed on an atmospheric side inclined surface 6 of a seal lip 4 at the specific distances through the specific angle alpha in relation to the direction of a seal lip tip edge 4a. The tips of the ribs 8 are so formed as to be concentrated to the tips of the ribs 7. Accordingly, the front surfaces of the ribs 7, 8 are brought in contact with a shaft in fitting to the shaft, however, the contact part is gradually decreased, and the surface pressure is gradually decreased. And the gap between the tip edge 4a of the seal lip 4 and the tip of the ribs 7, 8 is narrowed and lengthened, and the surface pressure of the seal lip tip 4a is decreased so as to be easily opened, thereby returning of collected oil is improved. |
