China Railway Construction Heavy Industry 8-Meter-Class Shield Machine Main Bearing Passes Application Review

Recently, at a technical review meeting held in Changsha, Hunan Province, the 8-meter-diameter main bearing for super-large shield machines, independently developed by China Railway Construction Heavy Industry (CRCHI), successfully passed the evaluation for equipment application. This achievement marks significant progress in the localization of core components for high-end underground engineering equipment in China.

The review panel consisted of 11 experts, including Qian Qihu, an academician of the Chinese Academy of Engineering, representing industry associations, research institutions, universities, and end-user organizations. The panel carefully reviewed the R&D process, technical approach, and testing procedures of the main bearing as presented by the development team, and conducted on-site inspections of the physical product and manufacturing processes.

After comprehensive evaluation, the expert panel unanimously concluded that the domestically produced main bearing has reached internationally advanced levels in key technical indicators such as load-bearing capacity and operational stability, with some performance metrics even surpassing those of foreign counterparts. Having passed rigorous load-testing verification, it fully meets the operational requirements of shield tunneling equipment and is ready for deployment in real-world engineering projects.

The main bearing, as the core transmission component of a shield machine, directly determines the equipment’s operational efficiency and service life. Due to its stringent requirements for high precision and reliability, it has long relied on imports, remaining one of the critical "chokepoints" in China’s high-end foundational machinery sector.

To break through these technological barriers, CRCHI initiated dedicated R&D efforts in 2019 with support from national and Hunan provincial key sci-tech projects. Focusing on critical aspects such as material selection, structural optimization, precision machining, and testing verification, the company progressively mastered the full-chain core technologies for main bearings. Today, it has established China’s largest production base for main bearings, achieving serialized development from small/medium-sized models to the world’s largest 8.61-meter-diameter product, with successful demonstrations in multiple projects.

The successful development of this 8-meter-class main bearing not only fills a domestic gap for core components in super-large shield equipment but also significantly enhances the supply chain’s self-sufficiency. Industry experts highlight that this breakthrough will accelerate the advancement of China’s high-end underground engineering equipment toward higher technical autonomy and global competitiveness in infrastructure machinery markets.