The spindle bearing (8m grade) for CRCHI mega shield tunneling machine clears operational feasibility assessment

On May 20, the 8-meter main bearing for the super-large diameter shield machine developed by China Railway Construction Heavy Industry passed the installation application demonstration in Changsha. The review expert group, led by Professor Qian Qihu of the Army Engineering University and Professor Chen Xiangsheng of Shenzhen University as the deputy group leader, and composed of 9 experts from industry associations, universities, and user units, including Su Zimeng, Jiang Yusheng, Zhu Weibin, Wu Zongyan, Sha Mingyuan, Xiao Mingqing, and Chen Jian, listened to the report of China Railway Construction Heavy Industry on the development of domestic 8-meter large-diameter main bearings, reviewed relevant technical information, and inspected the main bearing production line and actual products on site. Huang Changfu, member of the Standing Committee of the Party Committee and Vice President of China Railway Construction, made a summary speech at the meeting, Lei Shengxiang, an expert of China Railway Construction, attended the meeting, Zhao Hui, Secretary of the Party Committee and Chairman of China Railway Construction Heavy Industry, delivered a speech, and He Yongjun, Deputy Secretary of the Party Committee and Deputy General Manager, presided over the meeting.

The review expert panel unanimously concluded that CRCHI's 8-meter-class main bearing—independently designed, manufactured, and verified through reliability testing on the test bench—meets all design requirements with internationally advanced technical specifications, some of which lead globally, making it ready for practical engineering applications.

As the "heart" of shield tunneling machines, the main bearing represents a core foundational component addressing national strategic needs. It was listed among China's 35 "chokepoint" technologies constraining industrial development. Its localization has received strategic national support through initiatives like the Industrial Strengthening Foundation Project, National Key R&D Program, and the Industrial Foundation Innovation Development Catalog. The bearing's technical sophistication, manufacturing precision, and quality requirements position it at the pinnacle of global industrial and value chains.

In order to solve the contradiction that the core basic parts of the shield machine industry chain have long been dependent on imports and restricted by imported brands, since 2019, China Railway Construction Heavy Industry has relied on the support of key projects such as national ministries and commissions and Hunan Province to successively break through key technologies such as main bearing materials, design, manufacturing, and testing, and built the largest main bearing production base in China, realizing the independent development of multiple specifications of main bearings with a diameter of 8.61 meters and below, and completed the demonstration application of small and medium-sized diameter main bearings, effectively solving the "stuck neck" problem, ensuring the independent control of the industrial chain and supply chain, and achieving significant social and safety benefits.

The review expert group believes that the development and application of domestic main bearings has broken through the "last link" of the shield machine's "stuck neck" technology, and provided a solid guarantee for promoting the independent control of the industrial chain in the field of underground engineering; the major breakthrough in the localization of 8-meter-class main bearings for ultra-large diameter shield machines will greatly enhance the international competitiveness of my country's high-end underground engineering equipment industry.