On June 7, the first domestically-made shield main bearing successfully applied in construction jointly developed by China Railway Tunnel Bureau and Luoyang LYC Bearing Co., Ltd. was evaluated and accepted by the expert group in Hefei, indicating that the domestically-made shield main bearing has already been replaced with imported ones. The strength of the main bearing, China's shield machine made a breakthrough in the localization of the core components.
Leading the State Ministry of Industry and Information Technology, Zhou Yu, Executive Vice Chairman and Secretary General, China Bearing Industry Association, Song Zhenhua, Secretary General of China Tunneling Machinery Branch, China Construction Machinery Industry Association, Chen Jian, Deputy General Manager, China Railway Tunnel Group Co., Ltd., Kang Baosheng, Luoyang LYC Chairman of the Bearing Co., Ltd., Party Secretary Wang Xinying, Deputy General Manager Pang Bitao and leaders of more than 40 host companies in the tunneling industry participated in the assessment meeting.
The diameter of the main bearing that passed the evaluation and acceptance was 2.6 meters, and it can meet the continuous working of more than 15,000 hours for a 6-7 m diameter shield machine. The shield machine equipped with domestic main bearings is a product remanufactured by the China Railway Tunneling Bureau. From November 2016 to on-site use and completed in March 2018, the shield tunnelling machine accumulatively excavated 2369.65 meters, drilled 28.5 meters on the highest date, and drilled 397.5 meters at the highest monthly performance. The performance reached the level of the new shield machine. During the process, The main bearing did not have any abnormalities and was in good condition.
At the appraisal meeting, through the demonstration of the manufacturing, use, and monitoring of the main bearing, Zhou Yu, Executive Vice Chairman and Secretary-general of the China Bearing Industry Association, and Song Zhenhua, Secretary General of the China Construction Machinery Industry Association Machinery Division unanimously agreed The domestically-made shield main bearings are stable and reliable in engineering applications. The technical indicators have reached or partially surpassed that of similar foreign products and can meet the engineering requirements. The next step is to promote them within the industry.
Shield machine is a kind of tunnel construction equipment integrating machine, electricity, liquid, sensing and information technology. It is widely used in subway, railway, highway, municipal, hydropower and other tunnel projects. It is a measure of a country’s industrial manufacturing level. One of the major powers.
In the 1980s, the company began to research the localization of shield main bearings. In 2007, in order to solve the key technical constraints of such major equipment, the Ministry of Science and Technology launched the key technology of the “full-face roadheader” in the advanced manufacturing technology field of the National 863 Program. Development of main bearings for earth pressure balance shields. Zhou Lin, senior engineer at the company's technical center, said: 'We use the pre-technology accumulation and continue to innovate. We have developed the main bearing design analysis technology for shields. Quenching technology, surface non-destructive testing of surface hardened layers, precision machining technology, etc. achieved major technological breakthroughs, mastered a series of core technologies such as the formation, design, testing, and manufacturing of shield main bearings, forming a series of unique domestic materials. Heat treatment, testing standards. The developed product has been verified through experiments and applications to achieve good results. '
In 2015, in order to realize the localization of the core components of large-scale heavy equipment and to break through the bottleneck in the development of shield main bearings, China Railway Tunnel Administration Co., Ltd. combined with Luosha, established the “Development of main bearings for large-diameter composite shields” using the national key laboratory platform for aviation precision bearings. The research team carried out the development of shield main bearings. The China Railway Tunnel Administration conducted model analysis, acceptance of the shield main bearings, and conducted analysis of the monitoring data of the main bearings of the shield during the later period. Feedback data was used to make full use of the research and development advantages of the main bearings. The two parties cooperated to jointly promote the process of R&D of the main bearing of the shield. During the development process, the company created the welding technology of the special-shaped metal cage, established the design theory and method of the main bearing of the shield, and initially established the main bearing test and Application platform, the core problem of main bearing R&D is gradually being broken.
In September 2016, the shield main bearings jointly developed by the two parties passed the factory acceptance of industry experts. 'Domestic main bearings are products that combine the advantages of construction units and scientific research units. We are full of confidence, especially after passing the factory inspection and acceptance. Responsibility and obligation to carry out industrial tests, to bring scientific research products to the market sooner, and to realize the Chinese construction of shield main bearings.' said Hong Kairong, chief engineer of the China Railway Tunnel Agency.
After many efforts, the scientific research team decided to carry out an industrial test on the No. 3 line of the Hefei Rail Transit Line No. 3 project undertaken by the China Railway Tunnel Administration Bureau. After a year and five months, this shield machine with domestically-made main bearing and remanufacturing technology was integrated into one. The machine successfully completed the construction task, the bearing performance was good, and it had withstood the practice test. Next, this shield machine will move to the 6th item of the Hefei rail transit line 4 and continue to undertake the more arduous 2.7-km tunneling task.
Zhou Yu, Executive Vice Chairman and Secretary-General of China Bearing Industry Association, and Song Zhenhua, Secretary General of China Tunneling Machinery Branch of China Construction Machinery Industry Association, said in an interview that under the joint promotion of the bearing industry and digging industry, the high-end equipment core of shield machine is the main bearing. The successful implementation of localization applications has filled the gaps in China and has taken a substantial step forward in the drive for localization.
Chairman of the company, Party Secretary Wang Xinying, pointed out that the successful application of the main bearing of the shield machine is only a small step in the process of autonomy of the main bearing of the shield machine to realize the independence of the main bearing of the shield machine and the self-supporting of the shield machine bearing. , As well as high-end equipment supporting bearing autonomy, Luoxi still has a lot of work to do, still need to continue to work hard. The next Luoxi will continue to play an advantage in the manufacture of the main bearing, remanufacturing, testing analysis and evaluation, for the host user Provide more and more abundant, more cost-effective products and services, join hands with the host users, automate the key components of the shield machine, improve the core competitiveness of domestic high-end equipment, and make active efforts to build a strong equipment country contribution.
According to Chen Jian, deputy general manager of China Railway Tunnel Group Co., Ltd., China Railway Tunneling Administration, as a leading company in the field of domestic tunnels and underground engineering, has an unshirkable responsibility to shoulder the development of the national industry. The China Railway Tunneling Administration will also adhere to the high quality of Luoxi. The enterprises are strong and unite together to jointly make localization of the core components of the shield machine and make due contributions to the rapid development of the national industry.
At present, the company will continue to optimize and upgrade the research and development level of shield main bearings and increase the industrialization scale of such products. Together with China Railway Tunneling Administration, the company will jointly promote the process of shield machine construction in China.