| 摘要 |
PURPOSE: To effectively prevent muddy water from infiltrating into a bearing by fitting a dust cover for covering the end face of the journal part of a housing and an oil seal, to the outer periphery of the boss part of a pulley, and bringing a side lip, provided at the oil seal, into sliding contact with the side face of the dust cover. CONSTITUTION: In the case of muddy water being splashed on a pumping device, the infiltration of muddy water into a dust cover 11 can be suppressed by a labyrinth 14 between the short cylinder part 11b of the dust cover 11 and the short cylinder part 10d of an oil seal 10. Specially sand and pebbles contained in the muddy water are effectively hindered from entering into the dust cover 11 by the labyrinth 14. The muddy water permeating the labyrinch 14 is prevented from infiltrating into an inner peripheral lip L1 by the side lip L2 of the oil seal 10 brought into sliding contact with the inner side face of the dust cover 11. Even in the case of the muddy water permeating the side lip L2, infilration is prevented. |
