Naming ceremony for the domestically produced ultra-large-diameter shield machine main bearing.

On June 9, the "Wall Breaker," China's first ultra-large main bearing for shield machines, jointly developed by CCCC Tianhe and the Chinese Academy of Sciences, passed expert review by a panel of 9 academicians and renowned experts including Qian Qihu, Li Yiyi, and Chen Xiangsheng.

According to reports, the main bearing has a diameter of 8.01 meters and weighs 60 tons. It is China's first domestically developed main bearing for shield machines with the largest diameter and the heaviest single unit, and can be applied to ultra-large shield machines of the 16-meter class.

The expert panel unanimously agreed that the indicators of the domestically produced main bearing have reached the advanced level of comparable imported products. It is a supporting achievement for building China into a transportation powerhouse, holds great significance for the fields of shield tunneling and equipment manufacturing, and lays a technical foundation for the installation and application of ultra-large-diameter shield machines.

The domestically produced ultra-large-diameter shield machine main bearing.

The shield machine is major equipment for infrastructure construction, known as the "king of world engineering machinery," and undertakes the重任 of tunneling through mountains and crossing rivers and seas. Previously, whether it was the 15.03-meter ultra-large-diameter shield machine "Zhenxing," the 16.07-meter ultra-large-diameter shield machine "Yunhe," or China's first simultaneous excavation machine "Xingye," the domestic content rate had reached 98 percent, but the main bearing had always relied on imports from abroad. The main bearing is known as the "heart" of the shield machine and is a key core component of the shield machine's cutterhead drive system.

It is reported that in May 2021, the Chinese Academy of Sciences and CCCC Tianhe jointly established a collaborative research team to undertake the task of developing the shield machine main bearing, achieving the fully independent development of China's first 8.01-meter large main bearing.

Zhang Boyang, Party Secretary and Chairman of CCCC Tianhe, said in an interview that the successful passing of the expert panel review of the domestically produced main bearing marks that China has fully mastered integrated technologies such as independent design, precision machining, installation and commissioning, and life prediction of large heavy-duty shield machine main bearings, possesses import substitution capability, and has bridged the "last mile" toward full domestic production of ultra-large-diameter shield machines.