Recently, the tunneling of the Baicheng Tunnel, the longest coal transportation line in China, exceeded the mark of 3,000 meters and will soon be completed. The Baicheng Tunnel of Mongolia-Huayu Railway excavated the world's first horse-shoe shield machine independently developed by China. Bosch Rexroth, the world's leading supplier of transmission and control, offers a steady flow of driving force to this 'top performer'.
Bosch Rexroth hydraulic components used in the world's first horseshoe shield machine
As a national key transportation project, the Mongolia-Huayu Railway is a coal transportation line from Inner Mongolia to Central China with a total length of 1814.5 kilometers spanning seven provinces and autonomous regions in Inner Mongolia, Shaanxi, Henan and Jiangxi, among which the Baicheng Tunnel is 3,345 meters in length with a maximum depth of 81.05 meters , Designed as a double-track electrified railway tunnel with a speed of 120 kilometers per hour.Due to the special geographical environment, the Baicheng Tunnel section of the Mongolia-Huaihua Railway is located in the loess and weak geology in the northwest region, and the traditional tunnel construction methods are difficult and have many accidents. Effectively break the traditional restrictions and reduce the friction between the shield body and the formation, thereby reducing the propulsion resistance.This is the world's first tunnel excavation can greatly improve the utilization of the tunnel space, a decrease of 10% -15% Of the excavation area, thereby reducing the cost of the project and shorten the construction period.
'This is the first successful application of a horseshoe shield machine in China's loess tunnel and is a milestone in the history of railway tunnel construction technology and equipment. As a project owner, we are extremely honored.' 'Yang Xiaozhong, Application Manager, Industrial Hydraulic General Machinery, Rexroth China Said: 'For a long time, Bosch Rexroth and China Railway Engineering Equipment Group has maintained very close cooperation and we started in 2008 to develop domestically produced shield machine can be said to participate in the domestic shield machine from scratch, from there To the whole process of precision.Horseshoe shield machine shape is very special, which gives the hydraulic system in the design and component selection has brought some challenges, but we have excellent product technology and rich experience in the application, the successful solution to the technology On the difficulties, to ensure the successful completion of construction tasks.
Compared to the conventional conventional shield machine, the diameter of the horseshoe shield machine is larger and the shape of the cutter disc is also non-traditional, so the subsystems used in the conventional shield machine need to be greatly modified and even re-developed. Hydraulic system design and component selection also brought no small challenge.In order to find the most suitable component products, Rexroth team from the beginning of the project to actively participate in the design of system solutions for the horseshoe shield machine provides a range of products Components, including CA motor, A4 / A10 / A11 oil pump and GFT reducer, are used in the key components of each subsystem including propulsion, pipe assembly, screw conveyor, grouting, auxiliary system, etc. CA motor Small diameter, light weight and other features in the power consumption while reducing consumption.In addition, CA motor also has the impact resistance load and perfect internal symmetry, which can ensure that its torque in the rotation process consistent to ensure that the output force to achieve Perfect balance to minimize noise and vibration during construction. As a famous product of Rexroth, the A4 / A10 / A11 series oil pump won the majority of users at home and abroad Highly acclaimed and recognized, especially in the highly reliable equipment such as shield machine, A4 / A10 / A11 with its high pressure, high speed, high drive power and other characteristics, have a high market share At the same time, the volumetric efficiency of the series pumps is about 95%, the total efficiency of about 90%, has a strong resistance to cavitation, more efficient operation; A4 / A10 / A11 pump high material strength properties also ensure that its Resist the high pressure in operation, greatly extend the service life.
Rexroth A4A10A11 Bosch Rexroth pumps
Since entering China in 1978, Bosch Rexroth hydraulic system has been widely recognized for its safety and reliability, advanced technology and convenient operation, and has been involved in many large-scale construction projects in China. During the construction of the Wuhan Yangtze River Tunnel, Rexroth provided 72 belts The special oil cylinder with special sealing system ensures that the shield machine with a diameter of 11.38 meters will keep normal operation under difficult construction conditions. In the Three Gorges Project, Rexroth has provided the world's leading ceramic piston rod cylinder; in the construction of the Qinghai-Tibet Railway , The construction machinery equipped with Rexroth hydraulic system overcomes the harsh conditions of 4000 meters above sea level and ensures the smooth completion of the project with its stable performance. The year 2018 marks the 40th anniversary of China's reform and opening up and also marks the 40 years since Bosch Rexroth entered China. Rexroth witnesses the rapid economic development in China and is witnessing the industrial transformation in China. In the future, Rexroth will continue to grow together with Chinese enterprises, innovation in China and the Chinese forces by virtue of its own leading global product technology.