挖掘机旋转大齿圈是承载转台、起重臂及铲具作回转运动的重要零件，如齿圈断齿必须即时修复。　　一般情况下，单个齿损坏时常采用堆焊的工艺方法进行修复，当遇到一处多齿损坏时常采用更换大齿圈的方法。由于大齿圈安装在转台与底架梁之间，更换大齿圈的工序复杂、工作量大、? Excavator rotating ring gear is carrying turntables, booms and scoops for rotary motion of the important parts, such as ring gear broken teeth must be repaired immediately. Under normal circumstances, a single tooth damage often used surfacing process repair methods, often encountered in the replacement of a large gear ring when encountered a multi-tooth damage. Since the ring gear is installed between the turntable and the chassis frame, the process of replacing the ring gear is complicated and the workload is heavy.