Breakthrough in the development of main bearing of domestic super-large diameter shield machine
Newspaper, Changsha, October 12th (Reporter Yan Aihua, Long Jun)On the 12th, the 8.61m diameter shield main bearing independently developed by Chinese enterprises rolled off the assembly line in Changsha, Hunan Province. It is the integral shield main bearing with the largest diameter, the heaviest monomer and the highest bearing capacity in the world so far. Its successful development marks a major breakthrough in the development of domestic super-large diameter main bearings, and realizes the full coverage of domestic shield main bearings from small and medium diameter to super-large diameter.
This set of main bearings is independently developed by China Railway Construction Heavy Industry Group, which can be used to drive an 18-meter super-large diameter shield machine. The product weighs 62 tons and can withstand a load of over 10,000 tons. In the raceway plane with a diameter of more than 8 meters, the flatness is less than 20 microns, making it as difficult as carving flowers on rice grains.
As the "heart" part of the shield machine, the main bearing needs to face the extreme working conditions of the shield machine, such as overload, large eccentric load and frequency varying load. Its service life and reliability are restricted by many key factors, such as materials, design, manufacturing and testing, and the development difficulty is doubled with the increase of size. Previously, the key technology of main bearing of super-large diameter shield was monopolized by foreign enterprises for a long time.
Liu Feixiang, chief scientist of China Railway Construction Heavy Industry Group, introduced that in order to break through the weak link of the overall autonomy of the shield machine industry chain, Railway Construction Heavy Industry cooperated with upstream and downstream enterprises and universities to tackle key problems, and built the largest and internationally leading shield machine main bearing production line in Changsha Second Industrial Park of Railway Construction Heavy Industry, and successfully developed a full range of main bearings ranging from 3 meters to 7.6 meters; The world’s largest main bearing working condition simulation test-bed has been built, which has solved the worldwide problem that large-scale low-speed and heavy-load main bearings are difficult to test and verify.
It is understood that the main bearing of shield machine is included in 35 key technologies that restrict China’s industrial development, and it is the last link of the autonomy of the whole industrial chain of shield machine. With the smooth roll-off of the main bearing of the 8.61m domestic super-large diameter shield machine, Chinese enterprises have completely conquered and independently mastered the key core technologies of the whole series of main bearing products of the shield machine from design, materials to manufacturing and testing, thus giving the domestic shield machine a "China heart".