Application in CNC Machine Tool of Linear Motor
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The history of linear motors can be traced back to the unsuccessful linear Motors produced by Huisideng in 1840. In the following 160 years, linear Motors experienced three periods of exploration experiments, development and application, and use of commercialization. From 1971 to the present, the linear motor has finally entered a period of independent application. The application of various linear Motors has been rapidly promoted and many devices and products of practical value have been made. For example, linear motor driven steel pipe conveyor, coal transporter, various electric doors, electric windows and so on. The maglev train driven by a linear motor has a speed of more than 500km/h, which is close to the speed of aviation flight.
The research and application of linear motor in China began in the early 1970s. At present, the main achievements include factory driving, electromagnetic hammers, presses and so on. Although some achievements have been made in the study of linear motor in China, there is still a big gap in its application compared with other countries. At present, many domestic research units have noticed this.
In recent years, the use of linear motors for CNC machine tools has become particularly popular. The reasons are:
The high-speed processing developed in order to improve production efficiency and improve the processing quality of parts has now become a major trend in the development of machine tools. A responsive, high-speed, portable driving system has to be increased to 40 to 50 m/min. The peak feed speed can be reached by the traditional "rotating motor + ball screw" transmission form is 30m/min, and the acceleration is only 3m/s2. The linear motor drive worktable has a speed of 30 times that of the traditional transmission mode, an acceleration of 10 times that of the traditional transmission mode, and a peak of 10 g; Stigma increased by 7 times; The workbench driven directly by linear motor has no reverse working dead zone; Due to the small inertia of the motor, the linear servo system can achieve higher frequency response.
In 1993, the German company ZxCell-O introduced the workbench HSC-240 high-speed processing center driven by a linear motor. The peak speed of the spindle of the machine tool reached 24,000 r/min, the peak feed speed was 60n/min, and the acceleration reached 1G. When the feed speed is 20m/min, the contour accuracy can reach 0.004mm. The company immediately launched the HVM-800 high-speed processing center with a peak speed of 20000r/min for the spindle and a peak feed speed of 75.20 m/min.
Since 1996, Japan has successfully developed horizontal processing centers, high-speed machine tools, precision mirror processing machines, and high-speed forming machine tools that use linear Motors.
A stamping machine driven by linear motor has been developed by Zhejiang University in China. The Institute of Production Engineering of Zhejiang University has designed a parallel mechanism coordinate measuring machine driven by a cylindrical linear motor. In 2001, Nanjing Sikai Company launched a self-developed CNC linear electric locomotive bed driven directly by linear Motors. At the 8th China Machine Tool Exhibition in 2003, it exhibited the processing center obtained by the VS1250 linear motor launched by Beijing Institute of Technology High-tech Co., Ltd.. The peak speed of the spindle of the machine tool is 15,000 r/min.
The high-speed processing center using linear servo motors has become a key technology and product for major machine tool manufacturers to compete for research and development, and has achieved initial application and effectiveness in the automotive industry and the aviation industry. As a new generation of direct-drive servo actuators in high-speed processing centers, linear servo motor technology has also entered the industrial application stage at home and abroad. However, the domestic research in this area is still in the initial stage, and the gap is still very large. This paper has made some discussions on the application of linear Motors, and many technical problems still need to be worked out in the future. (Information source from network)
Linear motor