敞开式TBM主轴承外密封挡圈断裂脱落解决案例分析

Case Study of Breaking off of Outer Sealing Ring of TBM Main Bearing

敞开式TBM在长距离掘进过程中,由于频繁振动,可能造成主轴承外密封挡圈断裂、脱落。为解决现场更换难题,以国内某引水工程?8.5 m敞开式TBM为案例,结合施工现场条件对比分析3种处理方案的可行性、经济性,提出一种与原方案不同的创新解决方案,发明洞内TBM主轴承外密封挡圈维修新技术。在确定主轴承密封未损坏的情况下,改变原设计的螺栓连接方式,不拆卸刀盘,将新挡圈分4段焊接于转接座上。与常规处理的拆卸刀盘、开挖扩大洞安装整圆挡圈的方案相比,该方案作业难度大幅度减小,工作量在原方案基础上减少85%以上,耗时从最少需要4个月减少到0.5个月,能为主体工程的施工进度节约大量宝贵的时间,极大降低经济成本。

In long distance shield tunneling of open-type TBM,the outer sealing ring may cause breakage and shedding due to frequently vibration.In order to solve the problem,taking the open TBM with?8.5 m in a domestic water diversion project as an example,combined with the construction site conditions,the feasibility and economy of three treatment schemes are made a contrastive analysis.An innovative solution is proposed and a new maintenance technology for outer sealing ring of TBM main bearing is developed.If the main bearing seal is undamaged,the bolt connection mode of the original design can be changed.The new gear ring is installed in four sections and welded to the connecting seat and without removing the cutter head.If the main bearing seal is undamaged,the bolt connection mode of the original design can be changed.The new gear ring is installed in four sections and welded to the connezcting seat and without removing the cutter head.Compared with the regular treatment which is required to dismantle the cutter head and excavate and expand the hole to install the full circle,the new scheme is much easier and with reduction of the workload by more than 85%on the original basis,shortening the construction time from four months to half a month,which saved a lot of valuable time for the construction schedule and greatly reduced the economic costs.