Recently, the world's largest shield machine main bearing working condition simulation test bench, independently built by CRCHI, has completed verification of main bearings for shield machines of 7.6 meters and below, marking that domestic shield machine main bearings have achieved "test first, then go on duty,"and in one stroke filled the industry's testing gap.
Main Bearing Test Bench
Walking into the CRCHI production workshop, this test apparatus is running smoothly, with multiple auxiliary systems working in coordination to carry out rigorous extreme working condition tests for the core component of shield machines—the super-large-diameter main bearing.
In the past, China lacked the corresponding test verification conditions, making it difficult to carry out performance verification and life assessment of shield machine main bearings. Users "did not dare to use them and were unwilling to use them," which became the core bottleneck preventing domestic main bearings from moving from samples to engineering applications.
Shield machine main bearings operate for long periods in composite strata and withstand complex external forces such as ultra-heavy loads and large eccentric loads. Their performance directly determines the safety and success of major underground projects.
Targeting this series of "bottleneck" problems, CRCHI has built this performance and reliability test bench for super-large-diameter shield machine main bearings, bringing extreme working conditions such as ultra-heavy loads, large eccentric loads, and ultimate static loads into the laboratory. It conducts comprehensive performance verification—including structural strength, transmission performance, reliability, and ultimate load-bearing capacity of core main drive components—under loads far higher than actual working conditions, building a key "safety valve" for the research, development, and application of domestic main bearings.
The comprehensive loading system is the core capability of the test bench. The project innovatively adopts an internal load-bearing structure with dual-drive opposing tension and partitioned load control. Relying on an electro-hydraulic composite control system, it precisely reproduces axial and radial loads and overturning moments. Paired with an internal and external dual-circulation cooling system to ensure stable operation of the equipment under long-term high load, it can complete working condition simulation loading verification for shield machine main bearings of 7.6 meters and below.
Different from ordinary testing equipment, the test bench not only replicates the force environment, but also builds a multi-parameter sensing and monitoring system, synchronously collecting multi-source information, and relying on AI algorithms for joint state identification, achieving millisecond-level abnormal load warnings.
Test data is no longer recorded manually. Massive measured data is deposited into a dedicated test database, connecting bench tests with engineering site data to support forward design optimization of main bearings.
This test bench will provide technical support for major national projects such as plateau railways and deep-earth and deep-sea development, change the traditional R&D verification model in which domestic main bearings are "sent directly to the construction site," realize "test first, then go on duty," move extreme engineering tests forward into the laboratory, drive product iteration with measured data, and help achieve independent controllability of core components of shield machines.
Next, CRCHI will continue to promote technological breakthroughs and comprehensive substitution of domestic core components, providing core equipment support for safeguarding the security of the industrial chain and supply chain of major national engineering equipment.