Recently, CRRC Changchun Railway Vehicles Co., Ltd. (hereinafter referred to as "CRRC Changke") officially released the first domestically developed high-speed built-in bogie to the public. This marks a new breakthrough in China's deep control over the development of core technologies and key components of high-speed rail. The bogie is the running system of a rail vehicle and one of its core components, just like a person's legs. The built-in bogie is the movement of the axle box body, frame, primary suspension and other components of the bogie from the outer side of the wheel to the inner side of the wheel. The recently released built-in bogie is the first innovative product independently developed by CRRC Changke after 3 years of use in the field of high-speed trains. Its design speed is 400 kilometers per hour, and the test bench speed has reached 600 kilometers per hour, meeting the technical requirements for stability, smoothness, and other technical indicators required for high-speed train operation at a speed of 400 kilometers per hour. Zhou Dianmai, Chief Technical Expert of CRRC, stated that high-speed built-in bogies have gathered multiple innovations: for the first time in the railway industry, composite material plate spring technology has been adopted, fully utilizing the longitudinal dimensions of bogies and solving the problem of insufficient lateral space for built-in bogies; Adopting oil air suspension technology, the damping function of the first series of shock absorbers has been added with anti roll function, solving the problem of insufficient roll function in the first series of built-in bogies; Compared with traditional external bogies, high-speed internal bogies reduce weight by 20%, reduce vehicle energy consumption by 15%, decrease wheel rail wear by about 30%, reduce wheel rail noise by about 2 decibels, and lower maintenance costs for the entire lifecycle of the line and bogie by 15%. The operation of high-speed trains will be greener and more energy-efficient. (New Society)