According to the latest data, more than 10,000 sets of gear box for non-cold-area express EMU developed by Qishuyan Institution have been used in Beijing-Shanghai and Beijing-Guangzhou express lines. CSR is currently the only manufacturer of running gear for express train in China.
 

    Notably, major breakthrough has also been achieved by CSR in development of cold-area running gear box. So far express EMUs traveling at 380 km/h equipped with cold-area gear box developed by Qishuyan Institution has been operated safely on Haerbin-Dalian express line for more than 50,000 kilometer.
 

    A gear box for express train, consisting of gears, box framework, bearings and lubricating mechanism, is a gear transmission for the train, which transmits the power from electric motor to the train wheels to drive the train, and is one of the core components of the train. Generally, a gear set operating at a linear velocity of 25 m/s or higher is defined as high-speed gear box.

    When a train accelerates from 200 km/h to 380 km/h, linear velocity of driven gears will jump from 35 m/s to 70 m/s. Such a high speed is a great challenge to the gear performance, gear engagement and box sealing reliability. Haerbin-Dalian express line is the first express railway line operating across extremely cold areas in the world, where the lowest temperature in winter is -40°C, with snow depth up to 30 cm and depth of frost penetration up to 205 cm. Such extremely cold climate is a harsh challenge to stable operation of gear box for express train.
 

    To accommodate the hostile operating environment, Qishuyan Institution made special optimization to the gear box design, including selection of box framework and gear material and bearing configuration and simulated analysis of sealing of lubrication. The final product has been verified through bench test and evaluated by China Railway Corporation, and finally approved for on-board evaluation on cold-area lines.