矿用4m3挖掘机起重臂根部与回转平台用销轴连接．工作载荷大条件恶劣易磨损、裂纹而检修频繁难度较大。近年来一些挖掘机制造厂、大修厂不断采用新的检修、装配方法效果良好。1起垂臂根部两轴孔的检修（参见图1）按图1所示，依照在检测平台上划的十字中心线划一105mm孔的加园线 Mine 4m3 excavator boom boom and rotary platform with pin connection. Large working conditions, bad conditions, easy to wear and tear, cracks and frequent maintenance more difficult. In recent years, some excavators manufacturing plants, overhauling plants continue to adopt new maintenance, assembly method works well. 1 hanging from the root of the two-axis hole maintenance (see Figure 1) as shown in Figure 1, in accordance with the cross-sectional center line of the test platform designated 105mm hole plus Park Line