A Theory of Ball-screw Thermal Compensation

Thermal growth effects the reliability and accuracy of a machine tool, especially, as it relates to the High Speed Machining (HSM) technology. When axis speeds increase, the effect of thermal expansion of ballscrews will create large positional errors of the axes. In this paper, a piezo-integrated actuator and a load sensor are placed on the machine ballscrews, and the feedback from this arrangement becomes an ideal source for compensation of backlash and thermal expansion. This smart unit provides excellent performance of tolerance, the roundness test report reduced from 18.1 mu m to 10.00 mu m, and large cost savings in the manufacture of the machine tool.