Recently, the main bearing of the first domestic 6-meter TBM (Full-section tunnel boring machine) independently developed by ZYS passed the acceptance inspection. As a landmark equipment to measure the level of national industrial manufacturing, TBM is a key hardware support for the construction of large-scale mountain tunnels. It is mainly used for tunnel excavation in harder strata such as hard rock, which has high requirements on load-bearing capacity, impact resistance, reliability and high temperature resistance. Among them, the main bearing is the core component of TBM power transmission. Its load-bearing capacity and reliability determine the performance and service life of TBM. Previously, TBM main bearings had long relied on imports due to complex manufacturing processes, high raw material performance requirements, and immature design theories. The main bearings that our company passed the inspection have an outer diameter of 6010 mm, an inner diameter of 4920 mm, a weight of nearly 34 tons, an accuracy of P5 grade, and can be applied to TBMs with a diameter of 12 to 14 meters.

In the research and development, our company fully applies digital technology and uses self-developed slew bearing design and calibration analysis software. According to the calculation results, while ensuring the design indicators and safety margin, the bearing structural parameters are repeatedly calculated and adjusted to minimize the weight of the bearing, thereby achieving design cost reduction.

In order to break through the key technologies of TBM main bearing production and manufacturing, our company also gave full play to our own strengths. In view of the problems of large diameter of bearing rings and high processing accuracy requirements, the rings were processed in half and half, and the precision manufacturing of high-precision, large-size and complex profile rings was successfully achieved. In order to solve the problem of deformation of the inner and outer areas of thin-walled floating raceways, the "anti-deformation" quenching technology was innovatively developed, which not only reduces the amount of deformation during the heat treatment of floating raceways, but also increases the depth of the hardened layer. In addition, by establishing the relationship between the accuracy of parts and the accuracy of finished bearings, we optimally match the tolerances of bearing parts, improve the success rate of one-time assembly, and ultimately achieve non-destructive precision assembly of main bearings.

The acceptance of the 6-meter-class TBM main bearing marks that ZYS BEARING has broken through the key technology of TBM main bearings that are urgently needed for major national projects, and it is also a significant progress made in the overall localization process of China's TBM. In the future, we will use this product as a starting point to continue to promote the application of domestic main bearings and further contribute to improving the global competitiveness of China's TBM. For more information, please send email to sales@zys.com.cn.