With the development of direct drive technology, the comparison between the linear motor and the driving method of the traditional "rotary servo motor ball screw" has attracted industry attention. Now some of the world's most advanced machining center manufacturers are beginning to apply on their high speed machine tools.
Linear motor picture
In terms of accuracy, the linear motor has a simple reduction of the interpolation hysteresis due to the transmission mechanism, positioning accuracy, reproduction accuracy, and absolute accuracy. The position detection feedback control is higher than the "rotary servo motor ball screw" and is easy to implement. Linear motor positioning accuracy up to 0.1μm. "Rotary servo motor ball screw" up to 2~5μm, and Claim CNC-servo motor-no-gap coupling-thrust bearing-cooling system-high-precision rolling guide-nut seat - Workbench closed-loop The transmission part of the whole system should be lighter and the grating accuracy should be high. If you want to achieve high stability, the "rotary servo motor ball screw" should adopt dual-axis drive. The linear motor is a high-heating component. It needs to adopt a strong cold Measure. To achieve the same purpose, the linear motor has to pay more cost.
In terms of speed, the linear motor has a considerable Advantage, the linear motor speed reaches 300m/min, the acceleration reaches 10g, the ball screw speed is 120m/min, and the acceleration is 1.5g. From the comparison of speed and acceleration, the linear motor has considerable The advantage, and the linear motor will further improve the speed after successfully solving the heating problem, and the "rotary servo motor ball screw" is limited in speed and it is difficult to improve more.
In terms of life, the linear motor has a gap between the moving part and the fixed part, no contact, no wear and tear due to the high-speed reciprocating motion of the mover, and long-term use does not change the positioning accuracy of the motion, and is suitable for high-precision occasions. The ball screw can not guarantee the accuracy in the high-speed reciprocating motion. Because of the high-speed friction, the wear of the screw nut will affect the accuracy of the motion. Satisfy cannot be used for high precision requirements.