As the world’s largest consumer of machine tools, China’s lathe manufacturing industry has developed into a pillar industry. Due to the development of the automotive industry, the speed and efficiency of machine tools have put forward new requirements. It is understood that Japan’s machine tool CNC rate from the beginning of 40% to the current level of 90%, it took about 15 years. From China’s development speed, such as to reach the current level of Japan, it is estimated that it does not take so much time to improve the performance and quality of CNC machine tool functional components has become an urgent priority for the development of China’s machine tool industry.
In order to achieve its high performance, the machine tools produced in China on the drive using high-precision ball screw rate has improved greatly. The diameter of the ball screw and the size of the pitch on the machining center machine directly affects the accuracy of the machined parts. Especially under the cutting conditions of feed, the high-performance machining centers have chosen single head ball screws with small diameter and fine pitch. Of course, there are also some machining centers using coarse pitch multi-head ball screws. These machining centers generally use servo motor to drive the ball screw, but if the ball screw of machining center works, its rolling body makes spiral movement, the direction of its self-rotation axis is changed, so it will produce gyroscopic movement. When the gyroscopic moment in the motion exceeds the friction force between the ball body and the raceway, the rolling body will produce sliding, thus causing violent friction and making the temperature of the screw rise, while the vibration and noise will also increase, which will lead to the shortening of the life of the screw, thus greatly reducing the transmission quality of the ball screw. Therefore, a new and high-performance rolling screw, planetary roller screw, has been developed to better solve the above technical problems.
Along with the increasing development of new technology, the acceleration of machining center table will reach more than 3g and the inertia force of moving parts will be very large if in the case of high feed. So we are in the mechanical part of the design of the time, shall try to reduce the mass of the moving parts and rotary parts of the rotational inertia, and then further improve the machining center feed system stiffness, sensitivity and accuracy. Now most of the CNC machining center has been imported from Germany’s high-power linear servo motor, which can directly drive the table for linear motion, and with the light structure made of carbon fiber reinforced plastic table and linear rolling guide matched, which makes the machining center can achieve high feed rate and high precision machining.
As the machine speed increases, the use of guide rails also from sliding to rolling transformation. In China, due to lower machine speed and manufacturing costs, the use of sliding guide still accounts for most, but the number of machine tools using ball guide and roller guide is rising rapidly. As the rolling guide has high speed, long life, can add pre-pressure, easy installation and other advantages, with the machine performance and CNC requirements to improve, the use of rolling guide ratio is the inevitable trend.
Post time: Nov-08-2022
