【New Technology】China First Fully Automated Railway Bearing Press-Fitting Line Launched in Shaanxi province

On July 31st, reporters observed two intelligent press-fitting lines operating efficiently in the empty bearing press-fitting room of the Yulin Depot maintenance workshop of the Xi'an Railway Bureau Group Co., Ltd. These two fully automated, unmanned bearing press-fitting production lines are the first of their kind in China. The intelligent assembly lines integrate six robotic arms, 10 testing devices, and nearly 300 optical and contact sensors. Through automated transmission, intelligent selection, automated press-fitting, and real-time testing, they enable unmanned operation of the entire bearing press-fitting process.

On the intelligent assembly line, the stepper line moves smoothly, accurately delivering sets of qualified bearings to the work station. Then the robotic arm grabs them tacitly and installs a strong "knee joint" for a matching train wheel. The AI camera closely "watches" the operation quality of each link throughout the process.

"Wheels are the 'load-bearing core' of railway freight cars, and the quality of their maintenance directly impacts driving safety and transport efficiency. Bearing press-fitting is a crucial process in wheelset maintenance, demanding the highest precision," said Du Shiguo, Deputy Chief of the Technical Section at the Yulin Depot. "To this end, we've upgraded from 'human control' to 'machine control' through informatization and intelligent transformation. This not only improves process quality but also reduces labor intensity and safety risks for employees."

Since the beginning of summer, high temperatures have persisted across much of the country, increasing electricity consumption and demand for coal-to-energy trucks. As the only railway freight car maintenance base in the revolutionary base of northern Shaanxi, the Yulin Depot continuously supplies high-quality vehicles for the Haoji and Baoxi railways, major arteries for transporting coal from north to south.

"In the past, manual press assembly required four people, and improving the pass rate presented technical bottlenecks. Now, only one person is required to monitor the data in the background, significantly improving both efficiency and quality," said Hu Yong, a wheel axle installer in the Yulin Depot's maintenance workshop, pointing to the real-time production data scrolling on the screen.

Next to the shaft-wiping machine on the press assembly line, a ripple pattern resembling an electrocardiogram pulses on the display terminal. The equipment's "heartbeat" monitoring system is reading sensor data in real time, collecting input and output signals and information about the entire operation process. Using artificial intelligence algorithms, it assesses and predicts equipment status, providing a basis for preventive maintenance. This revolutionizes the traditional "after-the-fact" maintenance model, effectively reducing failure rates and increasing equipment reliability and service life.

At the same time, 18 AI cameras within the press assembly room provide 24/7 intelligent monitoring of key production line processes, utilizing AI image recognition technology to verify the correctness of the equipment's press assembly movements. If an anomaly is detected, the system immediately issues an alarm and automatically shuts down the machine, ensuring the production line's fault tolerance and rapid emergency response.

Since the fully automated, unmanned bearing press-fitting line went into operation this year, the press-fitting time for a single set of bearings has been reduced to 3.5 minutes, a 64.3% increase in efficiency compared to the average daily manual operation. The first-pass pass rate for bearing press-fits exceeds 98.5%. Currently, over 8,600 sets of qualified bearings have been safely press-fitted, meeting the needs of over 2,000 railway freight cars and providing sufficient vehicles for the transportation of energy and materials during the peak summer season.