Xinhua News Agency, Shenzhen, April 30 Topic: Liu Zhonghua: Heart and "Core" Communication

Journalists from Xinhua News Agency: Yin Peng, Mao Siqian, Li Sijia

There is a dojo in the shell of a snail, and there is a universe in between - from the "Shenwu" to the "Shen-15", behind the success of Chinese astronauts in patrolling the sky and exploring the universe, there are countless people's silent efforts, including Liu Zhonghua.

Liu Zhonghua, 52 years old, is a senior clock maintenance technician in the manufacturing department of Shenzhen Feiyada Precision Technology Co., Ltd. He has been engaged in this work for 33 years.

On April 25, Liu Zhonghua displayed the extravehicular spacesuit of "Shenzhou VII". Photographed by Mao Siqian, reporter of Xinhua News Agency

In 2003, Feiyada Company undertook the task of developing the aerospace watch for China's manned aerospace project, and Liu Zhonghua was responsible for the key work of the transformation, assembly and adjustment of the movement of the aerospace watch. "The on-board space watch worn by Yang Liwei, an astronaut of Shenzhou V, was our own. At that time, we had to assemble thousands of scattered parts into a complete watch. We had no relevant experience and had to test and debug it back and forth," Liu Zhonghua recalled.

In 2005, Feiyada Company undertook the task of developing the Shenzhou VII spacesuit watch. "Compared with Shenzhou V and Shenzhou VI, this space watch needs to be completely exposed in the space environment, and can withstand the ultralow temperature of minus 80 degrees Celsius and the strong magnetic field in space," Liu Zhonghua said.

It is reported that the ultralow temperature lubricating oil commonly used in the watch industry can only withstand minus 60 degrees Celsius, and there is a sign of solidification at minus 50 degrees Celsius. The team searched all the data, experimented and tried the lubricating oils used in aerospace at home and abroad, and selected the final oil after comprehensive comparison of molecular weight, surface tension, viscosity, volatilization time and other indicators.

"When using this special oil for the movement of the space watch, special technology is needed to light the oil." Liu Zhonghua said that the biggest challenge is to control the amount of oil. The smallest axle in the space watch is the pendulum wheel, which is only 7 wires in diameter, thinner than a hair, and the diameter of its escapement wheel and escapement fork is only 8 wires. It is extremely difficult to oil. The amount of oil must be just right, less can not play the role of lubrication, more will overflow, once the overflow, all parts must be disassembled, cleaned and reassembled... So, time after time, time after time, debugging, until completely qualified.

"Whether a mechanical watch works well depends on the master's debugging skills." Liu Zhonghua said that the measurement unit of the clock's accuracy is not mm, but "silk". 1 silk, about one eighth of the diameter of the hair. After years of training, Liu Zhonghua can judge whether the parts of the mechanical watch in his hand have moved 1 wire or 2 wires by holding the tweezers.

Over the past 20 years, Liu Zhonghua has participated in and successfully delivered 18 batches of space watches.

At the same time, Liu Zhonghua also participated in the research and development of Feiyada's civil independent movement, which was responsible for the secondary assembly and adjustment of the movement structure re research and development, and its performance was close to that of similar movements in Switzerland. Since 2019, he has successively completed the commissioning, assembly and maintenance of multiple complex movements, and successfully applied them to high-end products.

In 2016, Liu Zhonghua was awarded the title of "Top 100 Craftsman" by the Shenzhen Federation of Trade Unions, received special subsidies from the State Council, and set up the "Shenzhen Liu Zhonghua Precision Timing Manufacturing Master Studio"; In 2021, he was awarded the title of "South Guangdong Craftsman"; This year, it won the National May Day Labor Medal.

However, what excited and satisfied him most was the moment when he saw Chinese astronauts wearing watches walking out of space 15 years ago on TV.

"In my eyes, the movement of a watch is alive. It activates the movement from a standstill and makes a ticking sound, just like a human heart beating," Liu Zhonghua said. (End)