Recently, as the China National Academy of Metrology (hereinafter referred to as China Metrology Institute) took the lead in the "12th Five-Year" national major instrument project "high-end power plant torque and speed measurement equipment research and development and application of" acceptance by experts, China's high-end power plant measurement of key parameters to achieve a substantial increase will be China's rail transit, high-end vessels and other core components of the independent design and manufacture of industrial development to provide a full set of solutions to achieve high-tech leading the transformation of equipment manufacturing industry upgrade.
High-end power equipment is the heart of major complete sets of technical equipment such as advanced transportation equipment, large-scale power generation equipment and precision processing machinery, which occupies a pivotal position in the equipment manufacturing industry. In order to ensure the workability, efficiency, operational life and safety of the power plant, accurate measurement of key parameters such as torque and speed of the transmission shaft and other basic components must be carried out. The project leader, Zhang Yue, director of the Metrology Institute for Mechanics and Acoustics at China Metrology Institute, cited the example of a large ship. The drive spindles of its propulsion system usually need to withstand tens of thousands of Nm of torque. Fast maneuvering ships, instantaneous torque can even be as high as ten million cattle. If the torque and speed can not be measured and controlled quickly and accurately, the transmission spindles will be damaged and the service life of the equipment will be reduced. In severe cases, the spindle will fail.
It is understood that at present, China's high-end power equipment in the design, manufacture, the torque, speed and other key parameters of the measurement is still dependent on imports of high-end equipment. This seriously restricts the high-speed train bogies, large marine propulsion systems, aeroengines, wind turbines and other high-end equipment, the core components of the completely independent design and development. To this end, China Metrology Institute launched the research and application of relevant scientific instruments in support of the measurement of key parameters such as torque and speed of high-end power equipment under the support of the National Major Instruments Project in the 12th Five-Year Plan.
In 2012, on the basis of nearly 40 years of torque measurement experience, China Metrology Institute proposed the design of a 20 kN · m high-precision and high-torque standard device based on the new structure after repeated demonstration. "In order to reduce the friction torque and increase the measuring accuracy, we choose to use the static pressure air bearing instead of the traditional blade support, but the bearing capacity of up to 20kN · m air bearing, even if Germany does not have the processing Ability. "Zhang Yue said.
To this end, China Metrology Institute and cooperation units specifically on the static pressure air bearing manufacturing technology has launched a key research. After nearly four years of hard work, the project team overcame the problems of material handling, geometric quantity measurement, precision machining and assembly, and realized the self-development of large size, ultra-high precision and ultra-low friction torque air bearings, making China's air bearing manufacturing technology Fully beyond the level of imported products, not only high carrying capacity, support the steady state, but also more energy efficient.
In addition to reducing the component of uncertainty introduced by the bearing support, the device also takes full account of the uncertainty introduced by the arm, weight and other components, developed a series of arm system with independent intellectual property rights, suspension system, Code loading system and torque mechanism and other precision machinery and measurement and control systems, and to achieve the torque measurement process of automatic control. In order to ensure the accurate and traceable weight value, the project team also independently developed a set of high-accuracy and high-quality parameter measuring devices, achieving the accurate weighing of F1 class weights up to 2000kg in China for the first time.
As of the acceptance of the project, the measurement range of 20kN · m high-precision and high-torque standard device reached 100N · m ~ 24kN · m and the uncertainty was better than 0.002% (k = 2). The comprehensive technical indexes are leading in the world. The device expands the upper measurement limit of China's torque reference device from 5kN · m to 24kN · m, solves the problem of traceability of high-torque components such as high-end power equipment, breaks the core components such as high-torque measuring instruments and air bearings and completely relies on imports The situation for China's independent research and development related equipment R & D provides a solution and technical support.
The project has also successfully developed a dual-antenna radar velocimeter and an accelerometer dynamic characteristic calibration device for speed measurement range (20~350 km / h) for speed and acceleration parameters. This project is capable of enhancing the capability of China's high-speed railway and independently developing the homemade automotive airbag accelerometer And the product provides an important technical support.
It is reported that, at present, the project established a large mass parameter measurement device has been serving the national 863 project fuel cell energy efficiency analysis - hydrogen batteries, air bearings, torque standard devices and airbag accelerometer calibration devices have also been formed for the engineering, industry Technology files, will continue to lead China's independent manufacturing industry innovation level, driving "China's speed" to "China's quality" change.