为改善内河挂桨柴油机和齿轮箱的漏油现象，通过优化设计、对比试验等方法对挂桨机齿轮箱、接油盘进行技术升级改造。主要对齿轮箱盖板结构和接油盘进行改进：为齿轮箱盖板加装呼吸器；选用合适的吸油毡材料；为接油盘增设内衬，防止泄漏出的残油扩散。经过3艘挂桨渔船的实船系泊试验、航行换向试验以及多种材料、规格吸油毡的吸附油水混合物的对比试验，齿轮箱盖板加装呼吸器的技术改进效果明显，改进后3艘船均未发生透气口溢油现象，选取的吸油毡材料能快速吸附污油，对水没有吸附作用。试验结果表明，齿轮箱盖板增加呼吸器的改进方案切实可行、有效，并且具有推广价值；选用的吸油毡是配合接油盘使用和安装在挂桨齿轮箱螺旋桨轴管上的理想材料。

For the purpose of improving the oil leakage of oar-hung diesel engine and gear box in river, technical upgrading of oar-hung gear box and oil pan was carried out through optimization design, contrast test and other methods. It was mainly to improve the structure of gear box cover plate and the oil pan: install a respirator on the gear box cover plate; choose the appropriate oil-absorbent felt material; add a lining to the oil pan to prevent the leaked residual oil from spreading. Subject to mooring test, navigation and reversing test of 3 oar-hung fishing vessels and contrast test of adsorbed oil-water mixture of oil-absorbent felt of various materials and specifications, the effect of technical improvement after the gear box cover plate was installed with a respirator was obvious. After the improvement, no oil overflow occurred in the air port of the 3 oar-hung fishing vessels. The oil-absorbent felt chosen could quickly adsorb dirty oil but would not adsorb water. The results show that the improvement plan of installing the gear box cover plate with a respirator is feasible and effective and has promotional value; the oil-absorbent felt chosen  is an ideal material to be used together with oil pan and installed on the propeller shaft tube of oar-hung gear box.