NH220-C1型发动机配用在D80A-12型推土机上,这种发动机采用高精度的定型轴瓦,瓦片的耐磨合金很薄。检修时,只需按尺寸级别选好瓦片与轴径装配即可达到标准间隙,而不需经过镗瓦或研瓦处理。我们在检修这种发动机中,曾多次遇到安装瓦片后发生“研瓦”或“抱瓦”的现象。经检查发现,除一、七道轴承安装孔处,其余五道主轴瓦安装尺寸都小于标准0.03～0.018毫米。检查缸体发现,在缸体全长范围内轴瓦安装孔的 The NH220-C1 engine is used on the D80A-12 bulldozer. This type of engine uses high-precision shaping bushes and the wear-resistant alloy of the tiles is very thin. When overhauling, you only need to select the tile and shaft diameter assembly according to the size class to achieve the standard clearance, without going through the shingle or grinding tile processing. In overhauling this type of engine, we have repeatedly encountered the phenomenon of “grinding” or “warping” after installing tiles. Upon inspection, it was found that, except for the one or seven bearing mounting holes, the remaining five main bearing bushes were all smaller than the standard 0.03-0.018 mm. Inspect the cylinder and find that the bearing hole is installed in the entire length of the cylinder