Recently, China Railway Construction Corporation (CRCC) issued the "Decision on Commending the Top Ten Role Models of the Fifth 'Forever Railway Corps Cup' and the Eighth 'Top Ten Moral Models'."CRCHI (China Railway Construction Heavy Industry)Large-diameterTunnel Boring Machine (TBM)The Special R&D Team for Main Bearings won the "Top Ten Role Models" award

The Special R&D Team for Main Bearings of Large-Diameter TBMs at CRCHI won the "Top Ten Role Models" award

The Special R&D Team for Main Bearings of Large-Diameter TBMs at CRCHI was established in July 2019. Carrying forward the Railway Corps spirit of "cutting roads through mountains and building bridges across rivers," the team independently developed the world's largest 8.61-meter-diameter integral main bearing for TBMs, built an internationally leading high-end main bearing production line, created the world's largest comprehensive test bench for simulating main bearing operating conditions, achieved the development of main bearings for the full series of TBMs, and ensured the complete independent controllability of the main bearing industrial chain.

Bravely Serving as a "Pioneer" in Breaking Foreign Monopolies

TBMs that tunnel through mountains, cross rivers, and traverse seas are major national equipment supporting the country's economic development. For a long time, the main bearings—the core components of large-diameter TBMs—have been entirely dependent on imports, suffering from the pain of being "strangled at the neck" for years, and have been listed in the "National Industrial Strong Foundation Engineering Support Catalog" and the "National Industrial Foundation Innovation Development Catalog." A single imported main bearing of 8-meter class costs over ten million yuan, with a supply cycle of up to two years, and technical services are completely controlled by others.

The Special R&D Team for Main Bearings of Large-Diameter TBMs at CRCHI won the "Top Ten Role Models" award

In July 2019, CRCHI played the roles of "problem poser," "problem solver," and "examiner," voluntarily stepping forward and signing a military pledge. The company actively participated in national key R&D programs, led major technical equipment research projects of the State-owned Assets Supervision and Administration Commission of the State Council, focused on the integrated development of basic research and applied research, established a high-level innovation platform organization, selected 53 core technical talents in the fields of high-end underground engineering equipment and bearing manufacturing, formed a special R&D team, and established a research and design institute codenamed "197," concentrating efforts on breakthroughs inTunneling Machinethe "last link" of full industrial chain independence.

Forging a "Chinese Heart" for Major Technical Equipment

TBM main bearings face extreme harsh operating conditions and cannot be replaced inside tunnels, imposing extremely high requirements on reliability and safety; they sit at the very top of the large high-end precision bearing industrial chain. However, China's bearing industry has a high dependence on foreign sources for key basic materials, lacks independent design theories, core processes, and verification methods for large heavy-duty bearings, and the difficulty of product development increases exponentially with size.

The R&D team focused on basic research and frontier technologies, deployed its forces, and carried out in-depth technical breakthroughs in materials, design, processes, and testing. They studied dozens of material ratios, verified over a hundred design schemes, explored nearly a hundred process routes, and analyzed tens of thousands of sets of test data. After four years of hard work, they achieved full domestic production of long-life bearing steel, design methods and software, and manufacturing processes for TBM main bearings, broke through key technologies with independent intellectual property rights, obtained over a hundred authorized patents, and grasped the golden key to cracking the core code. They successively developed main bearings of various specifications ranging from 3 meters to 8 meters in diameter, achieving a transformation from 0 to 1 and from 1 to N.

Main Bearing of Large-Diameter TBM at CRCHI

Subsequently, the first trial production of the 8.61-meter-diameter main bearing was "excellent on the first attempt," winning an innovation battle that challenged a world-class problem, successfully forging a "Chinese Heart" for a major national equipment and firmly holding the key core technology of main bearings in their own hands.

On October 12, 2023, the independently developed 8.61-meter-diameter TBM main bearing rolled off the production line in Changsha. Its superb manufacturing craftsmanship is "comparable to carving flowers on a grain of rice." The product weighs 62 tons and can withstand loads of over ten thousand tons. It is the world's largest-diameter, heaviest single-unit, and strongest-load-bearing integral TBM main bearing to date, capable of driving super-large-diameter TBMs of 18 meters and above, effectively filling the gap in the super-large-diameter main bearing product spectrum.

Main Bearing of Large-Diameter TBM at CRCHI

Leading the New Track of Product and Industry Development

China's TBM main bearing industry has a weak foundation, with production line construction essentially blank. Core manufacturing equipment for key processes such as hard milling of gears and raceway grinding is highly dependent on foreign sources, posing great risks; ensuring the safety of the industrial chain is a matter of "national importance."

Starting from scratch, the R&D team focused on deep integration of industry, academia, research, and application, carrying out full-process development including production line planning, process layout, and equipment selection. They built China's first and largest-diameter CNC vertical grinding machine, CNC high-speed gear milling machine, and other domestic industrial mother machines, and established an internationally leading and domestically largest specialized production line covering the full process of main bearings.

The Special R&D Team for Main Bearings of Large-Diameter TBMs at CRCHI won the "Top Ten Role Models" award

Independently drawing hundreds of blueprints, conducting nearly a hundred simulation runs, and going through several rounds of review and demonstration, the team successfully developed a test bench structure capable of bearing ten-thousand-ton-class loads through disruptive innovation. They broke through key technologies such as intelligent parameter acquisition, electro-hydraulic control of complex loads, and accelerated loading fatigue testing, built the world's largest-diameter main bearing operating condition simulation test bench, successfully completed reliability verification of domestic main bearing products, boosted engineering verification and market application of key basic components, and made important contributions to accelerating the formation of new quality productive forces.

The Special R&D Team for Main Bearings of Large-Diameter TBMs at CRCHI won the "Top Ten Role Models" award

On December 4, 2023, the appraisal committee composed of academicians and experts including Ding Rongjun unanimously agreed that the project is technically difficult and highly innovative, possesses independent intellectual property rights, and has solved the "stranglehold" problem of main bearings for large-diameter TBMs. They gave high praise, stating that "the overall technology of the results has reached the international advanced level, with some reaching the international leading level."

Let us pay tribute to the role models, learn from and carry forward the spirit of the Railway Corps in the new era, persevere without slacking, strive to be the first, and contribute wisdom and strength to the high-quality development of the enterprise!