| 摘要 |
PURPOSE:To improve sealing durability, by setting a sealing part on the second screw boss and thereby preventing a screw load from being imposed on the sealing part. CONSTITUTION:The second propeller shaft 13A passes through the within of the first screw boss 12F of this contrapropeller and held by a bearing bush 15A. The second screw boss 12A is fitted with a sealing part 18 aand there makes up a watertight structure between it and the first screw boss. In this system, since no load of the second screw propeller is imposed on the sealing part 18, durability of the sealing part 18 is much improved. |
