Two world-class shield machines in China have been successfully off-line

On May 10, the industrial test results of the home-made shield/TBM main bearing reducer were released, and the first batch of home-made 6-meter conventional shield 3-meter diameter main bearing reducer passed the test, marking a new major breakthrough in the localization of the core components of shield in China.

The main bearing, known as the "heart" of the full-face tunnel boring machine (TBM), bears the main load during the operation of the TBM and is the key component of the cutterhead drive system. For a long time, the main bearings for shield machines in China have been imported. On July 24, 2015, China Railway, in conjunction with the domestic main bearing reducer technology superiority enterprises, applied for the national foundation project of industrial transformation and upgrading, undertook the construction project of the shield/TBM main bearing reducer industrial test platform, and carried out the key technology research and industrial test of the domestic main bearing reducer.

The shield/TBM main bearing reducer industrial test platform completed the production, assembly and commissioning in June 2018. After full investigation and demonstration, the test officially started on July 12, 2018. After three stages of no-load test, load sharing test and acceleration test, the 10000 hour equivalent life test of the main bearing reducer was completed on June 30, 2019. The application status is good, and all parameters and indicators operate normally. Domestic main drive frequency converter and 500 displacement hydraulic pump have stable performance and high reliability.

In April 2020, through the internal inspection of the main bearing and reducer, the review experts unanimously recognized the loading method and test conclusion of the test platform, and confirmed that the relevant performance of the domestic main bearing reducer applied to the metro shield machine met the standards and requirements, marking that China's shield/TBM core parts localization process has made new significant progress, which can effectively reduce the dependence on imported parts.

On the same day, the world's first small-turn full-face hard rock tunneling machine for mining was offline in the shield assembly workshop of China Railway Engineering Equipment Group. The equipment will be used in Sijichun Coal Mine in Guizhou Province, marking that the R&D of China Railway Equipment in the field of tunnel boring machines is moving towards a newer, more sophisticated, more cutting-edge and broader direction.

Previously, the largest domestic diameter (9.83 meters) open-type hard rock roadheader "Yunling" independently developed by China Railway Corporation was launched on May 8, and the equipment will be used for the water diversion project in central Yunnan Province. Its successful offline has once again set a new record for the diameter of domestic hard rock TBMs, marking the further improvement of the high-end level of research and development and manufacturing of Chinese TBMs. (Reporter Qi Huixia Xianqing)