In the process of continuous innovation of high-speed machining centers, it can be seen that making full use of the latest achievements in today's technology field, especially the latest achievements in drive technology and control technology, is the key to continuously improve the high-speed performance, dynamic characteristics and machining accuracy of machining centers.

In the past decade, the rapid progress of driving technology and control system has promoted the continuous innovation of machining center structure and the continuous improvement of performance. The application of electric spindle, linear motor, torque motor and fast CNC system plays a decisive role in improving the high-speed, high dynamic and high machining accuracy of the machining center.

Linear motor

At present, most high-speed machining centers for mold processing still use servo motors and ball screws to drive the linear coordinate axis, but some machining centers have adopted linear motors. Because this linear drive eliminates the transmission elements that convert rotary motion into linear motion, it can significantly improve the dynamic performance, moving speed and machining accuracy of the axis.

The machine tool driven by linear motor can significantly improve the productivity. For example, when machining electrodes for EDM, the processing time is 50% less than that of traditional high-speed milling machine.

Linear motor can significantly improve the dynamic performance of high-speed machine tools. Since most of the dies are three-dimensional surfaces, the tool axis must be constantly braked and accelerated when machining the surfaces. Only through high axis acceleration can the given contour be tracked with constant feed rate per tooth on a short path at a high track speed. If the curvature radius of the surface contour is smaller and the feed speed is higher, the required shaft acceleration is higher. Therefore, the axial acceleration of the machine tool greatly affects the machining accuracy of the mold and the tool durability.

Torque motor

In high speed machining center, the swing of rotary table and the swing and rotation of fork spindle head have been widely realized by torque motor. Torque motor is a synchronous motor. Its rotor is directly fixed on the components to be driven, so it has no mechanical transmission components. Like linear motor, it is a direct drive device. The angular acceleration of torque motor is 6 times higher than that of traditional worm gear drive, and the acceleration can reach 3g when swinging the fork spindle head. Because the torque motor can achieve extremely high static and dynamic load rigidity, the positioning accuracy and repeatability of the rotary shaft and the oscillating shaft are improved.

At present, high-speed machining centers of some manufacturers have adopted linear motor and torque motor to drive linear axis (X/Y/Z) and rotary oscillating axis (C and A) respectively.

It should be mentioned that the combination of the direct driven linear axis and the direct driven rotary axis makes all the moving axes of the machine tool have high dynamic performance and adjustment characteristics, thus providing the best conditions for high speed, high precision and high surface quality to process the mold free surface.