The first domestic shield machine main bearing, which was developed by the China Railway Tunnel Bureau and Luoyang LYC Bearing Co., Ltd., was developed in China for the first time. In June 7th, it was evaluated and accepted by the expert group in Hefei. It indicates that the main bearing of the shield has already had the strength to replace the main bearing of the imported main bearing. The domestic production of the core components of the shield machine has made a breakthrough.
The main bearing is called the “heart” of the shield machine, which bears the main load of the shield machine and is the key component of the cutter driving system. Before, the shield machine in our country is close to the world’s most advanced level, but the most important main bearings are all dependent on import, and the cost of the main bearing import is 1 billion yuan each year, which becomes our “card neck” technology.
Through the assessment and acceptance of the main bearing diameter of the shield machine 2.6 meters, the design life of 15 thousand hours, from November 2016 to March 2018 to complete the work to complete the construction task, has been working for 1300 hours, completed the expected goal. A total of 2369.65 meters were drifting, and the maximum day was 28.5 meters. During the construction process, no abnormality occurred, and the performance reached the new level of shield machine.
In 2007, the Luo axis began to undertake the National 863 plan advanced manufacturing technology field “the key technology of the full section tunnelling machine” – the development of the main bearing of the earth pressure balance shield, the design analysis technology of the shield main bearing, the single tooth back cold induction hardening technology of the large number tooth ring, the depth nondestructive testing of the surface hardening hardened layer and the precision processing technology. Major technical breakthroughs have been made in the fields of other aspects. On this basis, the China Railway Tunnel bureau is the lead, combined with the Luo shaft, and in 2015 set up a scientific research team of “large diameter composite shield main bearing development”, carrying out the development of the main bearing of 6 – 9 meters shield. In September 2016, the main bearing of the joint development was accepted by the factory, and the industrial test was started at the three line of Hefei rail transit, which was carried out by the China Railway Tunnel Bureau. The construction task was successfully completed in March 2018.
Next, the shield will fight for the 6 standard project of Hefei rail transit line four, and bear 2.7 km driving task. Los axis will also continue to optimize and enhance the development level of shield main bearings and improve its industrial scale.
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Post time: Jun-27-2018