Breaking News: China 8-Meter Diameter Spindle Bearing to Undergo Application Verification as Excavation Begins on Demonstration Section

In Changshu, Suzhou, Jiangsu Province, a bustling scene unfolds in the production workshop of CCCC Tianhe. Hu Xiaoqiang, a researcher at the Institute of Metal Research, Chinese Academy of Sciences, and his team are working closely with the company's technical personnel on the front lines, conducting final-stage debugging and verification of the main bearing for the tunnel boring machine (TBM) soon to be used in the Jiangxi expressway tunnel project.

This is not merely a routine equipment assembly; it is a crucial step towards achieving independent control over the core components of my country's TBMs and moving towards international leadership.

Hu Xiaoqiang said, "During the Spring Festival, we conducted stress analysis, structural optimization, and life evaluation of the domestically produced 8-meter diameter main bearing based on the specific working conditions of the application verification demonstration project, and have initially formulated a technical solution for the application verification of the domestically produced 8-meter diameter main bearing."

During the Spring Festival, Hu Xiaoqiang did not return to his hometown but instead led his team to the production line of the TBM main unit factory in Changshu, Suzhou, Jiangsu Province, to conduct the final-stage debugging and verification of the main bearing for the TBM soon to be used in the Jiangxi expressway tunnel project, ensuring the smooth progress of this major project.

For a long time, my country has relied on imports for the main bearings of its tunnel boring machines. The high procurement costs and the ever-present risk of supply disruptions have hung like a Damocles' sword, severely impacting the pace and safety of construction for a series of critical infrastructure projects, including subway tunnels, highways, and cross-sea passages. More than 20 institutions, including the Institute of Metal Research of the Chinese Academy of Sciences, collaborated to overcome the technological blockade and achieve independent development of large main bearings. Hu Xiaoqiang revealed that this year, domestically produced 8-meter diameter main bearings will be used in a demonstration excavation section for application verification.

Hu Xiaoqiang and his team understand that true self-reliance and control must begin at the source. They adhere to a research and development approach "starting from materials," building a comprehensive technical system covering the entire chain and successfully breaking through several key core technologies.

From the pure preparation and homogenization control of materials to low-stress regulation and deep quenching treatment; from heterogeneous material composite processes to high-precision machining and comprehensive life evaluation, every link is a tough nut to crack. After countless experiments and optimizations, the team finally formulated independent material specifications for key components of large main bearings, establishing a complete technical system from structural design and material preparation to processing, assembly, testing, and evaluation.

Today, this technical system has yielded fruitful results. The team has successfully developed 10 sets of main bearings with diameters of 3 meters, 6 meters, and 8 meters, suitable for various typical working conditions such as earth pressure, slurry, and hard rock. Among them, the domestically produced 3-meter main bearing has been first applied to the Shenyang Metro Line 1 East Extension project, operating stably in complex geological environments, with all performance indicators meeting design requirements, verifying the reliability of domestic technology.

The highly anticipated 8-meter ultra-large diameter main bearing represents a qualitative leap. Reviewed by an expert group led by Academician Qian Qihu of the Chinese Academy of Engineering, all indicators of the product have reached international advanced levels, with some indicators even reaching international leading levels, fully meeting the installation and application requirements of ultra-large diameter tunnel boring machines.

2026 will be a crucial year for the engineering application of domestically produced 8-meter main bearings. To ensure the flawless first excavation verification of the main bearing in the demonstration section of a highway tunnel in Jiangxi this year, the team, in collaboration with the main engine manufacturer CCCC Tianhe, tailored a complete application verification technical solution.

In future construction, the entire process, from the installation and testing of the tunnel boring machine (TBM) and real-time operational monitoring to post-service performance analysis, and then to supporting construction organization, operation and maintenance support, and emergency response, will be incorporated into a rigorous verification system. Through adaptability studies to actual working conditions, the main bearing structure will be further optimized, with the ultimate goal of creating a fully domestically produced large-scale TBM and successfully completing the excavation task of the demonstration section.

This TBM, equipped with a "Chinese heart," is about to begin tunneling through the mountains of Jiangxi. Every rotation of its bearing injects stronger self-reliance into my country's infrastructure construction. The localization of the main bearing not only means that related engineering construction costs are expected to decrease, but also strengthens the supply chain security of my country's high-end equipment manufacturing, laying a solid foundation for the smooth progress of more mega-projects in the future.